Understand how music is organized in less than 30 minutes. Designed for DJs, Trance & Techno producers. No advanced notation, no unnecessary jargon. Just the essentials.
Each chapter is designed to be read in 3 to 5 minutes. The diagrams are deliberately simplified to prioritize understanding. You can read everything in one sitting, or come back chapter by chapter as needed.
Throughout this guide, we use the letter naming convention (C D E F G A B) that's standard in English-speaking music communities and in every digital audio workstation (DAW). We primarily use the American terminology whole step / half step, with the British equivalents tone / semitone mentioned where helpful.
Before talking about scales or chords, we need to understand what a note actually is. The answer is both physical and cultural.
Sound is produced by vibration : a guitar string, a speaker membrane, air inside a tube. The faster the vibration, the higher the note. The slower the vibration, the lower the note.
This vibration speed is called frequency, measured in Hertz (Hz). The tuning reference note A, for example, vibrates at 440 Hz.
A note is one precise frequency. But our ears perceive sound in broader bands — this is the vocabulary shared by sound engineers, mixing engineers, and electronic music producers.
| Band | Range | Typical content |
|---|---|---|
| Sub-bass | 20 – 60 Hz | Sub, kick fundamental |
| Bass | 60 – 250 Hz | Bassline, kick body |
| Low-mids | 250 – 500 Hz | Warmth, low body |
| Mids | 500 Hz – 2 kHz | Vocals, leads, snares |
| High-mids | 2 – 4 kHz | Presence, clarity |
| Highs | 4 – 6 kHz | Air, brightness |
| Brilliance | 6 – 20 kHz | Hats, cymbals, sparkle |
Some sounds are harmonic, others are inharmonic — and whether to tune either of them to the key of the track is always a producer's choice, not a rule. A techno kick is harmonic enough to carry a real note (~50 Hz ≈ G1, ~65 Hz ≈ C2) ; some producers tune it so it locks in with the bassline, others leave it where it lands and let the bass do the harmonic work. A hi-hat is inharmonic — its partials aren't linked by musical ratios, so it has no clear fundamental — but its dominant frequency band still occupies a slot in the spectrum and can clash with the melody. Some producers filter or pitch-shift it ; others leave it raw and treat it as a colour layer rather than a pitched one. Every musical sound lives in the frequency spectrum ; some carry a note, others a colour.
Because between two notes an octave apart, you count eight white keys on a piano : C, D, E, F, G, A, B, C. An octave is the interval that brings us back to the starting point, but one « level » higher.
Figure 1 · The keyboard reveals a repeating pattern : 2 black keys / 3 black keys. This pattern repeats at every octave.
Every note has a precise frequency. The map below covers the range of an 88-key piano (A0–C8) : each key sits in one of the producer's frequency bands — sub-bass, bass, low-mids, mids, high-mids. Above C8 — in the highs and brilliance bands — there's no piano fundamental, and usually no melody playing, but the audible spectrum continues there with cymbals, hi-hats, and the upper harmonics of every pitched sound.
Figure 2 · The full 88-key piano range A0–C8 — just over seven octaves. Each octave doubles the frequency of the previous and occupies the same horizontal width — equal width for equal musical intervals, the way your ear actually hears them. The violet key marks A4 = 440 Hz, the universal tuning reference. The audible spectrum continues into the highs and brilliance bands above C8 (cymbals, hi-hats, upper harmonics), but no piano fundamental reaches there.
Two practical takeaways : a note doubles its frequency every octave (C1 = 32.7 Hz, C2 = 65.4 Hz, C3 = 130.8 Hz…), which is why each successive octave occupies the same width on the map above — equal spacing for equal musical intervals. And the fundamental of any pitched musical sound sits at exactly one key on this map. Whether you describe a frequency in note names or in Hz, you're pointing at the same place.
The octave is divided into 12 equal steps. This division is the foundation of all Western music.
Between two adjacent notes on a keyboard (white or black, it doesn't matter), there is one half step (called a semitone in British English). It's the smallest distance used in Western music.
Two consecutive half steps form a whole step (a tone in British English).
The distance between two adjacent keys on the keyboard.
Two half steps. One key is « skipped » between the two notes.
This guide uses the American convention — whole step and half step — throughout, because it lines up with how DAWs and modern producers describe intervals (you'll see "+12 semitones" in pitch shifters, "+1 step" in MIDI editors, etc.). The British equivalents tone and semitone mean exactly the same thing and are perfectly correct ; you'll meet them in older literature and conservatory training.
Every black key has two names, depending on which direction you approach it from :
So C♯ and D♭ are the same key. This is called enharmonic equivalence. It's like two routes to the same destination : the name depends on the path you took.
Figure 3 · The five black keys in one octave, with both their names.
Since C♯ and D♭ are the same key, why bother having two names ? The rule comes from how scales are spelled : in any major or minor scale, every letter (C, D, E, F, G, A, B) appears exactly once. We pick the sharp or the flat that respects this one-letter-per-degree rule.
Two concrete examples :
The takeaway : each key sticks to either sharps or flats — never both within the same scale. So when you see a producer chart that labels a note B♭ in one project and A♯ in another, they're the same physical key, but only one of them spells the scale correctly. Your DAW doesn't care ; readability for the human does.
There is no black key between E and F, nor between B and C. These two pairs of notes are therefore separated by only a half step, not a whole step. This irregularity in how black keys are arranged is the key to everything that follows.
A scale is simply a pattern of intervals. A formula. The major scale is one of the two patterns every producer should know — alongside the minor scale we'll meet in the next chapter.
You've heard the major scale a thousand times — its bright, settled quality is everywhere in pop, film and electronic music. What makes this pattern sound « happy » and « stable » isn't the notes themselves but the sequence of intervals between them.
Start from any note on the keyboard and apply this pattern : you'll get a major scale. The starting note is called the tonic, and it gives the scale its name.
The simplest scale of all, because it uses only the white keys.
Starting from G, we apply the same pattern. The pattern requires a whole step between the 6th and 7th notes, and a half step up to the tonic. To respect this rule, we must use F♯ instead of F natural.
The « black » notes used in a scale aren't arbitrary : they're mathematical necessities. They guarantee that the pattern W-W-H-W-W-W-H is respected. Without them, the scale wouldn't sound « major » anymore.
Where the major scale evokes brightness and joy, the minor scale brings a melancholic, dramatic, sometimes dark color. Same principle, different pattern.
Same logic as for the major scale : apply this pattern from any starting note and you get a minor scale.
Like C major, the scale of A minor uses no accidentals : all white keys.
Since A minor and C major use exactly the same notes, we say they are relative to each other. They share the same set of notes, but they have different centers of gravity — C for one, A for the other.
Every major scale therefore has its minor « twin ». To find it, simply go three half steps down (a minor third) from the major tonic.
| Major key | Notes that are sharp or flat | Relative minor |
|---|---|---|
| C major | — none | A minor |
| G major | F♯ | E minor |
| D major | F♯, C♯ | B minor |
| A major | F♯, C♯, G♯ | F♯ minor |
| E major | F♯, C♯, G♯, D♯ | C♯ minor |
| B major | F♯, C♯, G♯, D♯, A♯ | G♯ minor |
| F major | B♭ | D minor |
| B♭ major | B♭, E♭ | G minor |
| E♭ major | B♭, E♭, A♭ | C minor |
| A♭ major | B♭, E♭, A♭, D♭ | F minor |
| D♭ major | B♭, E♭, A♭, D♭, G♭ | B♭ minor |
A major key and its relative minor share the exact same set of notes — they're literally the same scale played from a different starting note.
The accidentals in the table above aren't arbitrary. The interval pattern W – W – H – W – W – W – H (major) and W – H – W – W – H – W – W (minor) force specific notes to be raised or lowered depending on where you start. G major needs F♯ because the pattern lands on a black key for the 7th degree — there's no choice. Classical notation collects these forced accidentals into what's called a key signature, written once at the start of the staff. In a DAW, the project « Key » field plays the same role : tell the software which scale you're in and you don't have to remember the accidentals at all — the pattern does the work.
There are two other common variants of the minor scale : the harmonic minor (7th degree raised by a half step) and the melodic minor (6th and 7th degrees raised when ascending, natural when descending). They enrich the emotional palette but all rely on the natural minor you've just learned.
An interval is the distance between two notes. It's the basic vocabulary for talking about chords, melodies and harmony.
This is a universal name that works for any pair of notes, their interval.
An interval is calculated in two steps : first the degree name (second, third, fourth…) by counting the note letters, then the quality (major, minor, perfect…) by counting the exact number of half steps.
| Interval | Half steps (from the tonic) | Example from C | Feeling |
|---|---|---|---|
| Minor second | 1 | C → D♭ | tense |
| Major second | 2 | C → D | natural step |
| Minor third | 3 | C → E♭ | melancholic |
| Major third | 4 | C → E | bright, happy |
| Perfect fourth | 5 | C → F | stable, open |
| Perfect fifth | 7 | C → G | very stable |
| Major sixth | 9 | C → A | sweet |
| Minor seventh | 10 | C → B♭ | tense, bluesy |
| Major seventh | 11 | C → B | cinematic |
| Perfect octave | 12 | C → C | identical |
Fourths and fifths behave differently from thirds : they are the same in both the major and the minor scale. That's why we call them perfect rather than major or minor.
By contrast, thirds are the big difference between major and minor : the third is what « colors » a chord. A major third (4 half steps) → major chord. A minor third (3 half steps) → minor chord.
As soon as you play multiple notes simultaneously, you enter the world of chords. The basic building block is the triad : three notes stacked together.
Take a scale. Start from the 1st note, skip one, take the next, skip again, take the third. You get a triad : three notes that sound together as a chord.
For example, in C major :
C + E + G = C major chord
Once you have three stacked notes, the distance between them determines the chord's quality — its character. Three qualities cover everything we'll need:
Major third + perfect fifth
(4 + 3 half steps)
open, bright feeling
Minor third + perfect fifth
(3 + 4 half steps)
intimate, sad feeling
Minor third + diminished fifth
(3 + 3 half steps)
tense, calls for resolution
Major and minor are the workhorses — every progression you'll write leans on them. The diminished triad is the special case : it appears exactly where the scale's interval pattern produces a 3+3 half-step stack — on the 7th degree of any major scale (vii°, e.g. B–D–F in C major) and the 2nd degree of any natural minor scale (ii°, e.g. B–D–F in A minor). You don't land on it as a home chord ; you pass through it for tension, then resolve elsewhere. We'll meet it on the diatonic tables of the next two chapters.
The three triad qualities above are the foundation. Stack a fourth note (a 7th), swap the third for the 2nd or 4th (sus2, sus4), or layer a 9th on top (add9), and you get the extension chords producers reach for most — covered in Chapter 9. Augmented and half-diminished are special cases that show up occasionally; we'll only flag them in passing where they're relevant.
A chord's name has two parts: root + quality. « C major » is the major triad rooted on C. « A minor » is the minor triad rooted on A. The recipe of intervals is the same for any root — pick a starting note, apply the recipe, and you have the chord.
Same fifth in both — only the third changes. A few examples to make the recipe concrete :
Compare C major and C minor: same root, same fifth — only the third changes. That single half step flips bright to dark.
« C minor » can mean two completely different things depending on context :
The chord lives inside the scale : C–E♭–G are the 1st, 3rd, and 5th degrees of the C minor scale. When someone says « the track is in C minor », they almost always mean the scale/key. When they say « play a C minor », they usually mean the chord. Context decides — and the same overlap exists for every root (« A major » is both a scale and a chord, etc.).
Take any major or minor scale and build a triad on each of its seven notes — using only notes from the scale. You get seven different chords that all live in the same key. These are the diatonic chords of the scale : the harmonic palette every progression in that key will draw from. They're labelled by the degree they sit on, written as Roman numerals (I, ii, iii, IV, V, vi, vii°) — not by note name. The next section explains the notation.
Roman numerals number chords by their scale degree — the position of the chord's root in the scale. The point of this notation is that it's scale-independent : « I – V – vi – IV » means the same harmonic move in any key, only the actual notes change.
Read « I – V – vi – IV » as « major on the 1st, major on the 5th, minor on the 6th, major on the 4th ». Transpose to any key — same shape, different notes. This is why producers and arrangers write progressions in Roman numerals: it captures the harmonic intent, independent of the key the track ends up in.
You now know what a triad is, what gives it its quality, and how the seven diatonic chords get labelled. The next two chapters work through them concretely : in the major scale (Chapter 7), then in the minor scale (Chapter 8).
In any major scale, the seven diatonic chords follow a fixed pattern of qualities — same shape in every major key, only the actual notes change.
On each degree of the major scale, stack thirds (the skip-take-skip pattern from the previous chapter) using only notes from the scale. You get seven interconnected chords:
| Degree | Roman numeral | Notes (in C major) | Type |
|---|---|---|---|
| 1st (tonic) | I | C – E – G | major |
| 2nd | ii | D – F – A | minor |
| 3rd | iii | E – G – B | minor |
| 4th (subdominant) | IV | F – A – C | major |
| 5th (dominant) | V | G – B – D | major |
| 6th | vi | A – C – E | minor |
| 7th | vii° | B – D – F | diminished |
In any major key, the qualities follow this pattern : I major, ii minor, iii minor, IV major, V major, vi minor, vii° diminished. The pattern doesn't change — only the actual notes do. Transpose the table to G major and you get G – Am – Bm – C – D – Em – F♯°.
The progression I – V – vi – IV (C – G – Am – F in C major; A – E – F♯m – D in A major; G – D – Em – C in G major) is one of the most used progressions in pop, dance and film music over the past 50 years. Now that you know Roman numerals, you'll recognise it everywhere.
The natural minor scale yields its own seven diatonic chords, with a different mix of qualities. This is the harmonic palette behind most melancholic, cinematic and EDM tracks.
Same skip-take rule on each degree, this time using the natural minor pattern. In A minor (relative of C major — same notes, different center of gravity) :
| Degree | Roman numeral | Notes (in A minor) | Type |
|---|---|---|---|
| 1st (tonic) | i | A – C – E | minor |
| 2nd | ii° | B – D – F | diminished |
| 3rd | III | C – E – G | major |
| 4th (subdominant) | iv | D – F – A | minor |
| 5th | v | E – G – B | minor |
| 6th | VI | F – A – C | major |
| 7th | VII | G – B – D | major |
In any natural minor key, the qualities follow this pattern : i minor, ii° diminished, III major, iv minor, v minor, VI major, VII major. Notice that A minor and C major share exactly the same chords — they're the same diatonic palette, only re-centred.
In minor-key dance music, the progression i – VI – III – VII (Am – F – C – G in A minor) is everywhere — house, trance, progressive, cinematic, pop. It's sometimes called the « Andalusian » or « epic » progression. Listen for it once and you'll start hearing it across the whole spectrum.
Inside any scale, the seven diatonic chords don't all do the same job. Each plays one of three roles — tonic, subdominant, or dominant — and most progressions are just a sequence of these roles, dressed up with different chord choices.
Every diatonic chord falls into one of three families that describe its harmonic gravity :
Home. The chord of rest and arrival. Where progressions return to. Stable, settled.
Departure. Motion away from home. Opens up the progression. Neutral tension.
Pull. The strongest pull back to the tonic. Unstable, wants to resolve. The « leading » chord.
The textbook order is T → SD → D → T : leave home, drift further, build tension, resolve. Most popular progressions are dressed-up versions of this skeleton.
In a major key, the seven diatonic chords distribute across the three families like this :
| Function | Chords | In C major | Notes |
|---|---|---|---|
| Tonic (T) | I, iii, vi | C, Em, Am | I is the strongest tonic; iii and vi are softer substitutes. |
| Subdominant (SD) | ii, IV | Dm, F | IV is the classic « departure » ; ii is its minor-flavoured twin. |
| Dominant (D) | V, vii° | G, B° | V is the textbook dominant. vii° is rare on its own (often used as a passing chord). |
Same idea, different distribution :
| Function | Chords | In A minor | Notes |
|---|---|---|---|
| Tonic (T) | i, III, VI | Am, C, F | i is home ; III and VI are tonic substitutes (and account for much of minor-key colour). |
| Subdominant (SD) | ii°, iv | B°, Dm | iv is the smoother choice for landing ; ii° (diminished) is a tenser, darker variant — perfect for passing tension or atmospheric textures. |
| Dominant (D) | v | Em | The diatonic v is weak — there's no leading tone in natural minor, so v doesn't pull strongly to i. Tracks that want a strong cadence borrow harmonic minor to raise it to V (E major in A minor). |
| Subtonic | VII | G | The major chord built on the subtonic (the whole-step-below-tonic 7th degree). Strictly, not a dominant — no leading tone, no tritone tension toward i. But its strong harmonic landing makes it the EDM go-to substitute for the missing dominant — listen for it in i – VI – III – VII. |
Natural minor genuinely has a 4-role structure (T / SD / D / Subtonic) instead of major's 3 — that's a consequence of the missing leading tone, not a quirk to memorise.
A chord is defined by the set of notes it contains, not by the order they sit in. Change which note is at the bottom and you've made an inversion — same chord, same name, different feel.
A triad has three notes. Whichever one sits in the bass (the lowest voice) defines the position :
Root in the bass.
Stable, settled.
the « default » voicing
3rd in the bass.
Lighter, less rooted.
often used in passing
5th in the bass.
Suspended, unstable.
wants to resolve
All three are still C major — they contain the same C, E, and G. Only the order changed. But the bass note carries enormous harmonic weight, so each inversion feels different.
Inversions are written with a slash. The letter before the slash names the chord ; the letter after names the note in the bass.
| Notation | Chord | Bass note | What it is |
|---|---|---|---|
| C | C major | C (the root) | Root position |
| C/E | C major | E (the 3rd) | 1st inversion |
| C/G | C major | G (the 5th) | 2nd inversion |
Slash chords also cover non-inversion cases — C/D means « C major over a D bass note », a sonority that's not strictly an inversion of C (D isn't in the chord). Slash notation is the standard way to specify « these chord notes, that bass note », whether or not it's a textbook inversion.
The biggest practical reason to use inversions is voice leading : choosing voicings that make notes move by small steps between chords rather than big leaps. Smaller leaps sound smoother, especially in a bass line and in a pad.
Compare C – F – G – C (the classic I – IV – V – I) in two voicings :
Bass leaps : C → F → G → C
Bass jumps a 4th up, a 2nd up, a 5th down. Feels punchy but choppy.
Bass walks : C → A → B → C
Bass moves by step. Same chord progression, smoother feel.
Three places where inversions earn their keep in a producer's session :
A triad — root, third, fifth — is just the starting point. Stack one more note, replace the third, or add a high colour tone, and you unlock the chord families that fill modern productions: 7ths, sus chords, and add9.
Take a triad. Apply the same skip-take rule one more time and you land on the 7th degree above the root. Stacking it on top gives a four-note chord — the seventh chord.
Like triad qualities, the quality of the added 7th isn't a free choice — the scale picks it. Within a major scale, the diatonic 7ths are :
| Degree | Chord | In C major | Type |
|---|---|---|---|
| I | Imaj7 | C – E – G – B | major 7th |
| ii | ii7 | D – F – A – C | minor 7th |
| iii | iii7 | E – G – B – D | minor 7th |
| IV | IVmaj7 | F – A – C – E | major 7th |
| V | V7 | G – B – D – F | dominant 7th |
| vi | vi7 | A – C – E – G | minor 7th |
| vii° | viiø7 | B – D – F – A | half-diminished (m7♭5) |
In a natural minor scale, the same logic gives a different distribution :
| Degree | Chord | In A minor | Type |
|---|---|---|---|
| i | i7 | A – C – E – G | minor 7th |
| ii° | iiø7 | B – D – F – A | half-diminished |
| III | IIImaj7 | C – E – G – B | major 7th |
| iv | iv7 | D – F – A – C | minor 7th |
| v | v7 | E – G – B – D | minor 7th |
| VI | VImaj7 | F – A – C – E | major 7th |
| VII | VII7 | G – B – D – F | dominant 7th |
Notice that A minor's 7ths are the same chords as C major's, just relabelled — they share the same notes.
A sus chord takes a triad and replaces the 3rd with the note next to it — either the 2nd (giving sus2) or the 4th (giving sus4). The chord ends up with no third at all, so it's neither major nor minor. It sits « suspended » — open, undecided.
3rd replaced by the 2nd.
(root + 2nd + 5th)
bright, airy, modern
3rd replaced by the 4th.
(root + 4th + 5th)
tense, expectant
A sus chord wants to resolve back to its parent triad — the suspended note slides by step onto the missing 3rd. Csus4 → C (F drops to E) is one of the most natural moves in popular music, used to delay arrival on a target chord. Csus2 → C works the same way (D rises to E).
An add9 chord is a major (or minor) triad with the 9th stacked on top — the same note as the 2nd, but an octave up. Unlike a sus2, the 3rd is still there : you keep the chord's major or minor quality and add a high colour tone.
This pair is the most common chord-chart confusion, so it's worth nailing :
| Notation | Notes (in C) | Contains the 7th? | Sound |
|---|---|---|---|
| Cadd9 | C – E – G – D | No | Bright triad with a sparkly top note. |
| C9 | C – E – G – B♭ – D | Yes (♭7) | Dominant 7 + 9. Jazzy, funky, urgent — wants to resolve to F. |
The rule : writing « 9 » on its own (like C9, G9) implicitly means « dominant 7th plus 9th ». Writing add9 means « just the 9, leave the 7th out ». In a producer's session, Cadd9 is the bright pad chord ; C9 is the funky bass-house stab.
Here is the ultimate tool. In one diagram, it connects every key and reveals the hidden logic of harmony.
Start from C major, at the top of the circle (no accidentals). At each step in the clockwise direction, you go up a perfect fifth and add one sharp to the key signature. Going counter-clockwise, you go down a fifth and add one flat. The relative minors are placed inside the circle.
Figure 4 · The circle of fifths. Each bubble also shows its Camelot and Open Key designation (see reference tables below). Neighboring keys share the most notes in common.
The closer two keys are on the circle, the more notes they share, and therefore the easier it is to modulate (change keys) between them without sounding strange. That's why composers often move from C major to G major or F major : they are direct neighbors.
DJs rediscovered the circle of fifths under another name. When two tracks are mixed together, if their keys sit too far apart on the circle the result sounds dissonant. Mixing in neighboring (or identical) keys keeps the harmonic energy coherent — this is harmonic mixing.
The three « safe » moves :
These three moves guarantee a maximum of shared notes between the two tracks. The further apart on the circle, the fewer notes in common, and the higher the dissonance risk. To make this work fast in a booth, DJs created a numeric notation for keys — see the reference tables below.
Two numeric notations encode keys in a way that makes harmonic mixing fast at a glance. Both are built on the same circle of fifths idea : ±1 on the number means a neighbor on the circle, and flipping the letter on the same number means switching between a key and its relative major / minor.
| Key | Camelot | Open Key |
|---|---|---|
| C | 8B | 1d |
| G | 9B | 2d |
| D | 10B | 3d |
| A | 11B | 4d |
| E | 12B | 5d |
| B | 1B | 6d |
| F♯ | 2B | 7d |
| D♭ | 3B | 8d |
| A♭ | 4B | 9d |
| E♭ | 5B | 10d |
| B♭ | 6B | 11d |
| F | 7B | 12d |
| Key | Camelot | Open Key |
|---|---|---|
| Am | 8A | 1m |
| Em | 9A | 2m |
| Bm | 10A | 3m |
| F♯m | 11A | 4m |
| C♯m | 12A | 5m |
| G♯m | 1A | 6m |
| D♯m | 2A | 7m |
| B♭m | 3A | 8m |
| Fm | 4A | 9m |
| Cm | 5A | 10m |
| Gm | 6A | 11m |
| Dm | 7A | 12m |
Same Camelot number across the two tables = relative major / minor pair (C major and A minor both share the number 8). Adjacent number on the same letter = neighbor on the circle of fifths (8B → 9B = C → G).
So far, we've worked with two scale flavours : major and natural minor. There are five others. Together, the seven modes are the colour palette of the diatonic family — same notes, different tonics, distinctively different moods. This chapter zooms in on the three that show up most in electronic music.
Take a major scale. Now play it from a different starting note, treating that new note as the tonic. The set of pitches is unchanged, but the pattern of intervals around the tonic rotates — and so does the chord that sits on the tonic. You've made a mode.
Concretely : the seven notes C – D – E – F – G – A – B are C major. Start the same notes from D and treat D as home — the result is D Dorian. Same notes, but the tonic is D, the chord on D is minor (D – F – A), and the interval pattern relative to that tonic is different from major. Each of the seven white-key starting points gives a mode :
| Mode | White-key example | Pattern from tonic | Quick read |
|---|---|---|---|
| Ionian | C – D – E – F – G – A – B | W W H W W W H | = the major scale |
| Dorian | D – E – F – G – A – B – C | W H W W W H W | minor with a raised 6th |
| Phrygian | E – F – G – A – B – C – D | H W W W H W W | minor with a lowered 2nd |
| Lydian | F – G – A – B – C – D – E | W W W H W W H | major with a raised 4th |
| Mixolydian | G – A – B – C – D – E – F | W W H W W H W | major with a lowered 7th |
| Aeolian | A – B – C – D – E – F – G | W H W W H W W | = the natural minor scale |
| Locrian | B – C – D – E – F – G – A | H W W H W W W | minor with lowered 2nd and lowered 5th — unstable |
Notice that you already know two modes : Ionian is what we've been calling major, and Aeolian is the natural minor. The five others are simply different rotations of the same diatonic note set.
In practice, three modes dominate electronic and pop music alongside the standard major and minor: Dorian, Phrygian, and Mixolydian. Each one shifts a single note relative to its parent (major or minor), and that one note carries the whole flavour.
Minor with a raised 6th.
W H W W W H W
soulful, groovy, less « sad » than natural minor
Minor with a lowered 2nd.
H W W W H W W
dark, Spanish, cinematic, exotic
Major with a lowered 7th.
W W H W W H W
bright but rooted, bluesy, rock-leaning
Double the frequency = go up one octave. The octave is divided into 12 equal half steps.
A half step (semitone) = distance between two adjacent keys. A whole step (tone) = 2 half steps.
Interval pattern :
Interval pattern :
½ step up = sharp (♯). ½ step down = flat (♭). C♯ and D♭ are the same key.
Every major key has a minor twin with the same key signature. It's 3 half steps below the major tonic.
Major third = 4 half steps (bright sound). Minor third = 3 half steps (melancholic sound).
Identical in major and minor. Fourth = 5 half steps, fifth = 7 half steps.
Root + major third + perfect fifth. Example : C – E – G.
Root + minor third + perfect fifth. Example : A – C – E.
In major : I ii iii IV V vi vii° — three major (I, IV, V), three minor (ii, iii, vi), one diminished (vii°).
In minor : i ii° III iv v VI VII — three minor (i, iv, v), three major (III, VI, VII), one diminished (ii°).
Clockwise = +1 sharp per step. Counter-clockwise = +1 flat per step. Neighbors are « friendly » keys.
A sharp (♯) or flat (♭) added to a note. Raises or lowers it by a half step.
A chord that adds the 9th (the 2nd, an octave up) to a triad without including a 7th. Cadd9 = C–E–G–D.
A triad with two stacked major thirds (4+4 half steps). Symbol : + (e.g. C+). Uncommon in EDM; mentioned in passing only.
The closing harmonic move of a phrase, typically a progression that resolves tension back to the tonic. V → I is the textbook cadence.
Two DJ-oriented systems for naming keys numerically (1–12) so harmonic compatibility between tracks is easy to read at a glance. Adjacent codes are related by a fifth.
Using all 12 semitones, including notes outside the current scale. Opposite of diatonic.
A diagram arranging the 12 keys in a clockwise sequence of perfect fifths (C, G, D, A, E…). Adjacent keys share six of seven notes.
Belonging to a single scale. The seven white keys are the diatonic notes of C major; the diatonic chords are the seven triads built using only those notes.
A triad with two stacked minor thirds (3+3 half steps). Symbol : ° (e.g. B°). Tense, used as transitional tension; appears as vii° in major and ii° in minor.
The 5th degree of a scale, and the chord built on it. Carries strong tension that pulls back to the tonic.
Two different names for the same pitch. C♯ and D♭ are enharmonic equivalents — same key on a piano, two spellings.
A triad with extra notes added — a 7th, 9th, sus2, sus4, add9, etc. The chord families producers reach for once basic triads start to feel plain.
The defining pitch of a sound — the note your ear names when you hear it. Other frequencies (partials, overtones) sit on top, but the fundamental is what gives the sound its note name.
A sound is harmonic when its partials line up to give a clear pitch (most instruments, voice). Inharmonic when they don't, so no defined pitch (cymbals, hi-hats, snares).
A variant of the natural minor with the 7th degree raised by a half step. Adds a leading tone, so V can be played as a major chord.
The distance between two notes, measured in half steps. Has names (major third = 4 half steps, perfect fifth = 7, etc.).
Re-stacking a chord so the root is no longer the lowest note. C–E–G (root position) → E–G–C (1st inversion) → G–C–E (2nd inversion).
The set of sharps or flats that apply throughout a piece, written once at the start of the staff. Equivalent to setting the project Key in a DAW.
The 7th degree of a major scale, a half step below the tonic. Pulls strongly to the tonic — the source of cadential resolution.
A variant of the natural minor with the 6th and 7th raised when ascending, returning to natural when descending. Smooths out melodic motion.
A scale built by starting on a different degree of a parent scale. The seven modes of the major scale (Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian) each have their own colour. See Chapter 13.
The interval between a note and another at twice (or half) its frequency. Both share the same letter name.
A 7-half-step interval (C → G). Stable, « open » quality. The fifth used in both major and minor triads.
Two scales that share the same set of notes but have different tonics. C major and A minor are relatives.
The note a chord is built on. The C in a C major chord (C–E–G).
The position of a note within a scale, numbered 1 to 7. The 1st degree is the tonic, the 5th the dominant, etc.
The smallest distance in Western music — one fret on a guitar, one key (black or white) on a keyboard. C → C♯, B → C, E → F.
A four-note chord — a triad plus the 7th. Three flavours producers use most : maj7 (Cmaj7), m7 (Cm7), and dominant 7 (C7 = major triad + minor 7th).
The 4th degree of a scale, and the chord built on it. « Pre-dominant » — sets up the tension that V resolves.
The 7th degree of a natural minor scale, a whole step below the tonic. Doesn't pull as strongly as the leading tone.
Suspended chords. The 3rd of the triad is replaced by the 2nd (sus2 : C–D–G) or the 4th (sus4 : C–F–G) — neither major nor minor in flavour.
The 1st degree of a scale, its « home » note. Gives the scale its name.
Moving a melody, chord, or progression up or down by a fixed interval, preserving all relative distances. C major → D major shifts everything up two half steps.
A three-note chord built by stacking thirds (root + 3rd + 5th).
A 6-half-step interval (e.g. F → B). The most dissonant interval in tonal music; the engine of V-chord tension.
Two half steps. Distance from C to D, or D to E. American « whole step » and British « tone » are interchangeable.
This guide is only a starting point. The best way to truly understand music theory is to hear it. Open your favorite DAW, or put your fingers on a piano, and play the examples. The concepts will come alive instantly.
© 2026 Gérald Croes / EOSS2K — Licensed under CC BY-NC-ND 4.0. Share freely with attribution. No commercial use, no derivatives.