Semitone
The smallest standard step in twelve-tone equal temperament, such as C to D-flat or E to F.
For songs, instruments and productions
Music theory you can put to work
Build scales and chords, translate Roman numerals, hear progressions, download WAV and MIDI files, choose modal colors and turn theory into parts for guitar, keyboard, voice or a DAW.
Foundations
Hear relationships before memorizing labels
Notes gain meaning from a tonic, rhythmic placement and surrounding harmony. Learn scale degrees and intervals as reusable relationships, then connect them to exact note names on your instrument.
Whole tone
Two semitones, such as C to D.
Scale degree
A note’s numbered position relative to a tonic. Scale degree 1 is tonal home.
Interval
The measured distance between two notes. Intervals shape melody, chords and voice leading.
Tonic
The pitch or chord heard as home. A collection of notes can support more than one tonic.
Key
A tonic plus a network of expected scale degrees and harmonic functions.
Mode
A scale collection organized around a particular tonic and characteristic degrees.
Enharmonic spelling
Different names for the same sounding pitch, such as F-sharp and G-flat. Spelling shows musical function.
Interval palette
The same interval can feel different in a melody, bass line or chord. These descriptions identify common uses, not fixed emotions.
| Interval | Semitones | Common use |
|---|---|---|
| Unison | 0 | stability, doubling, rhythmic force |
| Minor second | 1 | friction, urgency, chromatic approach |
| Major second | 2 | stepwise motion, openness, suspended color |
| Minor third | 3 | minor-triad identity, compact expressive leap |
| Major third | 4 | major-triad identity, bright consonance |
| Perfect fourth | 5 | suspension, quartal openness, melodic lift |
| Tritone | 6 | maximum diatonic instability, dominant pull, ambiguity |
| Perfect fifth | 7 | strong consonance, power-chord stability |
| Minor sixth | 8 | wide expressive leap, minor color |
| Major sixth | 9 | wide warmth, major or Dorian color |
| Minor seventh | 10 | dominant or modal openness |
| Major seventh | 11 | sharp pull toward the octave, major-seventh color |
| Octave | 12 | pitch-class return at a new register |
Interactive theory lab
Turn formulas into notes and chords
Calculations use practical flat spellings for readability. Choose enharmonic spellings that fit the key when writing notation.
- Formula
- Common tendency
- Songwriting use
Progression player and downloads
ReadyPreview synthesized chords, save a WAV for listening, or export MIDI for a DAW. Rendering stays in this browser.
WAV contains the selected synthesized sound. MIDI contains editable notes, tempo and timing. Results may sound different after a DAW assigns its own instrument.
- Scales
- Progressions
- Arrangement levers
This is a starting palette, not an emotional rule. Change tempo, rhythm, voicing, register and timbre to reshape the result.
Move clockwise to add one sharp and move counterclockwise to add one flat. Adjacent keys share six of seven notes, which makes them useful modulation destinations.
CAmGEmDBmAF-sharp mEC-sharp mBG-sharp mF-sharpE-flat mD-flatB-flat mA-flatFmE-flatCmB-flatGmFDm
Scale atlas
Choose a pitch collection and establish its center
A scale formula describes intervals above the tonic. Its musical identity becomes clear when melody, bass, harmony and emphasis reinforce the tonic and characteristic notes.
Major
1 2 3 4 5 6 7
- Tendency
- clear tonal hierarchy, open or direct
- Harmony
- I ii iii IV V vi vii°
- Use
- Broad tonal songwriting. Contrast stable I with predominant ii or IV and dominant V.
Natural minor
1 2 flat 3 4 5 flat 6 flat 7
- Tendency
- dark, grounded, reflective
- Harmony
- i ii° III iv v VI VII
- Use
- Minor loops and modal songwriting. Raise scale degree 7 when a stronger dominant resolution is needed.
Harmonic minor
1 2 flat 3 4 5 flat 6 7
- Tendency
- dramatic minor with a strong leading tone
- Harmony
- i ii° III+ iv V VI vii°
- Use
- Use major V or diminished vii° to create decisive movement back to minor tonic.
Melodic minor
1 2 flat 3 4 5 6 7
- Tendency
- smooth, sophisticated minor tension
- Harmony
- i minor-major 7, ii7, III+maj7, IV7, V7, vi half-diminished, vii half-diminished
- Use
- Useful for jazz color, minor-key lines and dominant alterations derived from its modes.
Major pentatonic
1 2 3 5 6
- Tendency
- open, singable, spacious
- Harmony
- often layered over major I, IV and vi
- Use
- Strong for hooks because it omits the half-step tensions of scale degrees 4 and 7.
Minor pentatonic
1 flat 3 4 5 flat 7
- Tendency
- earthy, direct, riff-friendly
- Harmony
- works across many minor, blues and rock contexts
- Use
- Build guitar riffs and vocal motifs, then target chord tones when the harmony changes.
Blues
1 flat 3 4 flat 5 5 flat 7
- Tendency
- gritty, expressive tension between fixed and bent pitch
- Harmony
- commonly used over dominant-seventh blues harmony
- Use
- Treat the blue note as motion or inflection, not necessarily a resting pitch.
Major blues
1 2 flat 3 3 5 6
- Tendency
- buoyant with blues inflection
- Harmony
- major and dominant settings
- Use
- Blend major pentatonic warmth with a chromatic approach into scale degree 3.
Whole tone
1 2 3 sharp 4 sharp 5 flat 7
- Tendency
- floating, unresolved, symmetrical
- Harmony
- augmented triads and dominant chords with sharp 5
- Use
- Use briefly for dreamlike transitions, augmented harmony or dominant tension without a clear leading tone.
Whole-half diminished
1 2 flat 3 4 flat 5 flat 6 6 7
- Tendency
- symmetrical suspense around diminished harmony
- Harmony
- diminished seventh chords
- Use
- Sequence short motifs by minor thirds over a diminished chord.
Half-whole diminished
1 flat 2 sharp 2 3 sharp 4 5 6 flat 7
- Tendency
- dense dominant tension
- Harmony
- dominant 7 flat 9, sharp 9, sharp 11 and 13 colors
- Use
- Apply to an altered dominant before resolution, especially when several altered tensions appear.
Chromatic
all twelve pitch classes
- Tendency
- maximum pitch availability, little hierarchy by itself
- Harmony
- defined by surrounding tonal or atonal organization
- Use
- Use approach notes, passing tones, planing or tone rows. Rhythm and target notes must create coherence.
Phrygian dominant
1 flat 2 3 4 5 flat 6 flat 7
- Tendency
- intense dominant color with a wide flat-2 to 3 leap
- Harmony
- major I with flat II and minor iv colors; fifth mode of harmonic minor
- Use
- Build a tonic pedal riff and feature flat 2 resolving to 1 or rising to 3.
Lydian dominant
1 2 3 sharp 4 5 6 flat 7
- Tendency
- bright upper color with dominant looseness
- Harmony
- dominant 7 sharp 11
- Use
- Use over a non-resolving dominant or a bright major chord with flat 7 and sharp 11.
Altered scale
1 flat 2 sharp 2 3 flat 5 sharp 5 flat 7
- Tendency
- compressed dominant instability
- Harmony
- dominant 7 with flat 9, sharp 9, flat 5 or sharp 5
- Use
- Aim altered notes toward nearby notes in the resolution chord.
Double harmonic major
1 flat 2 3 4 5 flat 6 7
- Tendency
- strong tonic frame with two augmented-second gaps
- Harmony
- major tonic with flat II, minor iv and leading-tone tension
- Use
- Keep a tonic drone and expose the flat 2, 3, flat 6 and 7 carefully so the color remains identifiable.
Hungarian minor
1 2 flat 3 sharp 4 5 flat 6 7
- Tendency
- dark, angular and highly charged
- Harmony
- minor tonic with augmented fourth and leading tone
- Use
- Use for dramatic riffs, sequences and pedal-point writing rather than dense chord stacks.
Bebop dominant
1 2 3 4 5 6 flat 7 7
- Tendency
- flowing dominant lines with chord tones aligned to downbeats
- Harmony
- dominant seventh
- Use
- Run eighth notes so chord tones land on strong beats, treating natural 7 as a passing tone.
Diatonic modes
Change the tonal center and characteristic degree
Modes are more than major scales beginning on different notes. Establish the modal tonic with repetition, bass, cadence and a characteristic pitch that distinguishes the mode from ordinary major or minor.
| Mode | Formula | Characteristic | Tendency | Useful vamp |
|---|---|---|---|---|
| Ionian | 1 2 3 4 5 6 7 | major 3 and major 7 | stable major, clear resolution | I-IV-V-I or I-vi-ii-V |
| Dorian | 1 2 flat 3 4 5 6 flat 7 | minor 3 with natural 6 | minor but mobile, soulful, hopeful tension | i-IV or i-ii |
| Phrygian | 1 flat 2 flat 3 4 5 flat 6 flat 7 | flat 2 | compressed, dark, confrontational | i-flat II or tonic pedal with flat-2 motion |
| Lydian | 1 2 3 sharp 4 5 6 7 | sharp 4 | bright, suspended, weightless | I-II or Imaj7 with sharp 11 |
| Mixolydian | 1 2 3 4 5 6 flat 7 | major 3 with flat 7 | open, communal, rock or folk directness | I-flat VII-IV-I |
| Aeolian | 1 2 flat 3 4 5 flat 6 flat 7 | flat 3, flat 6 and flat 7 | natural-minor gravity, reflective or heavy | i-VI-III-VII or i-VII-VI-VII |
| Locrian | 1 flat 2 flat 3 4 flat 5 flat 6 flat 7 | flat 2 and flat 5 | unstable, brittle, unresolved | i diminished-flat II or short half-diminished passages |
Chord construction
Stack intervals, then choose voicing and register
A chord symbol identifies a pitch structure. Its actual sound depends on which note is in the bass, how widely notes are spaced, what is omitted or doubled and which instrument plays each register.
| Chord | Formula | Common character |
|---|---|---|
| Major triad | 1 3 5 | stable major foundation |
| Minor triad | 1 flat 3 5 | stable minor foundation |
| Diminished triad | 1 flat 3 flat 5 | compressed instability |
| Augmented triad | 1 3 sharp 5 | symmetrical expansion |
| Suspended 2 | 1 2 5 | open chord without a third |
| Suspended 4 | 1 4 5 | suspension that often resolves 4 to 3 |
| Power chord | 1 5 | thirdless strength that avoids major or minor identity |
| Add 9 | 1 3 5 9 | triad with open upper color |
| Major 7 | 1 3 5 7 | smooth major color with internal tension |
| Dominant 7 | 1 3 5 flat 7 | major-minor tension that often resolves down a fifth |
| Minor 7 | 1 flat 3 5 flat 7 | soft minor extension |
| Half-diminished 7 | 1 flat 3 flat 5 flat 7 | minor-key predominant or Locrian color |
| Diminished 7 | 1 flat 3 flat 5 double-flat 7 | symmetrical leading-tone tension |
| Minor-major 7 | 1 flat 3 5 7 | minor triad with sharp upper tension |
| Major 9 | 1 3 5 7 9 | expanded major color |
| Minor 9 | 1 flat 3 5 flat 7 9 | expanded minor warmth |
| Dominant 9 | 1 3 5 flat 7 9 | dominant function with added motion |
| 13 chord | 1 3 5 flat 7 9 13 | full dominant or modal color; fifth and eleventh are often omitted |
| Slash chord | chord/bass note | an inversion or independent bass color that can smooth voice leading |
Diatonic chord maps
Major triads
I ii iii IV V vi vii°
Major, minor, minor, major, major, minor, diminished.
Major sevenths
Imaj7 ii7 iii7 IVmaj7 V7 vi7 vii half-diminished 7
The dominant seventh on V contains the tritone that drives tonal resolution.
Natural-minor triads
i ii° III iv v VI VII
The natural minor v lacks a leading tone and creates a softer return.
Functional minor
i ii° III+ iv V VI vii°
Raise scale degree 7 to create major V or diminished vii° leading back to i.
Roman numerals and function
Separate harmonic relationships from exact pitches
Roman numerals label chord roots relative to a key. Uppercase indicates major, lowercase indicates minor, a degree sign indicates diminished and accidentals before the numeral alter the root. The same I-V-vi-IV relationship can therefore move to any key.
Tonic
I, vi and sometimes iii in major; i and III in minor
rest, identity, arrival
Predominant
ii and IV in major; ii° and iv in minor
departure and preparation for dominant
Dominant
V, V7 and vii°
instability directed toward tonic
Plagal motion
IV-I or iv-i
a softer return without dominant leading-tone force
Deceptive motion
V-vi in major or V-VI in minor
expected tonic is delayed by a tonic-family substitute
Backdoor motion
iv7-flat VII7-I in major-oriented harmony
chromatic approach to tonic from a borrowed dominant color
Progression library
Choose motion that supports the song’s job
Progression labels describe common tendencies, not emotional guarantees. Harmonic rhythm, bass, melody, cadence, groove and voicing decide whether the same numerals feel tender, aggressive, comic or bleak.
| Use | Roman numerals | Context | Motion |
|---|---|---|---|
| Direct resolution | I-IV-V-I | major | clear setup, tension and arrival |
| Pop continuity | I-V-vi-IV | major | forward loop with stable tonic and relative-minor turn |
| Reflective pop | vi-IV-I-V | major beginning on vi | introspective opening that grows toward dominant |
| Doo-wop cycle | I-vi-IV-V | major | nostalgic circular motion with a strong turnaround |
| Singer-songwriter descent | I-V over 7-vi-IV | major | stepwise bass descent and gentle inevitability |
| Mixolydian rock | I-flat VII-IV-I | Mixolydian | open, anthem-like loop without leading-tone pull |
| Dorian lift | i-IV | Dorian | minor center brightened by natural scale degree 6 |
| Phrygian pressure | i-flat II | Phrygian | tight half-step tension above tonic |
| Lydian openness | I-II | Lydian | bright suspended color from sharp scale degree 4 |
| Natural-minor drive | i-VI-III-VII | minor | broad minor loop with cinematic continuity |
| Descending minor | i-VII-VI-V | harmonic minor at V | stepwise descent ending in strong dominant tension |
| Minor lament | i-v-VI-iv | minor | dark circular motion with a softer dominant role |
| Andalusian cadence | i-VII-VI-V | minor or Phrygian-inflected | descending bass and decisive dominant return |
| Jazz resolution | ii7-V7-Imaj7 | major | predominant to dominant to tonic |
| Minor jazz resolution | ii half-diminished 7-V7-i | minor | compact minor-key functional cadence |
| Rhythm changes bridge | III7-VI7-II7-V7 | chain of secondary dominants | successive dominant pushes around the circle of fifths |
| Gospel plagal rise | I-IV-iv-I | major with borrowed iv | warm expansion followed by bittersweet return |
| Chromatic mediants | I-flat VI-flat III-I | chromatic | large cinematic shifts joined by common tones |
| Blues turnaround | I7-IV7-I7-V7-IV7-I7 | blues | tonic remains flexible while dominant-quality chords create grit |
| Neo-soul loop | Imaj7-iii7-vi9-ii9-V13 | major | smooth extended harmony with connected inner voices |
| Dream-pop drift | Imaj7-vi7-IVmaj7-iv6 | major with modal mixture | soft major field ending with borrowed-minor color |
| Tritone-sub turnaround | ii7-flat II7-Imaj7 | jazz chromatic | chromatic bass motion replaces V7 with its tritone substitute |
Beyond diatonic harmony
Add one clear source of color
Chromatic harmony works best when the listener can hear what remains constant. Preserve tonic, common tones, bass direction, motif or rhythm while one harmonic dimension changes.
| Technique | What it does | How to use it |
|---|---|---|
| Modal mixture | Borrow from the parallel major or minor, such as iv or flat VI in major. | Change one color while keeping the tonic recognizable. |
| Secondary dominant | Use V of a destination chord, such as V of vi before vi. | Create temporary directed tension without fully changing key. |
| Tonicization | Briefly make a non-tonic chord sound like a local tonic. | Confirm it with its applied dominant, then return to the main key. |
| Modulation | Establish a new tonic for a meaningful span. | Use a pivot chord, direct shift, common tone, chromatic sequence or dominant preparation. |
| Chromatic mediant | Move between major or minor chords whose roots are a third apart. | Preserve one common tone or move voices by semitone for cinematic cohesion. |
| Tritone substitution | Replace V7 with a dominant chord a tritone away. | Retain the guide-tone tritone while creating chromatic bass motion. |
| Pedal point | Hold or repeat one bass note beneath changing chords. | Create unity while upper harmony changes color. |
| Planing | Move one chord shape in parallel. | Prioritize contour and timbre over functional voice leading. |
| Line cliché | Move one inner voice chromatically while the chord or bass remains stable. | Generate motion inside a sustained tonic area. |
Scale and progression tendencies
Start with a palette, then shape the actual feeling
Theory describes relationships and common listening tendencies. A scale, chord or progression does not guarantee one emotion because tempo, rhythm, register, voicing, timbre, melody and context all affect the result.
Open and direct
- Scales
- Major or major pentatonic
- Progressions
- I-IV-V-I or I-V-vi-IV
- Arrangement
- mid register, clear triads, steady pulse
Warm and nostalgic
- Scales
- Major with borrowed iv, Mixolydian or major pentatonic
- Progressions
- I-vi-IV-V or I-IV-iv-I
- Arrangement
- gentle tempo, close voice leading, tape-like timbre
Reflective and bittersweet
- Scales
- Natural minor, relative-major mixture or Dorian
- Progressions
- vi-IV-I-V or i-VI-III-VII
- Arrangement
- descending lines, restrained rhythm, unresolved extensions
Dark and grounded
- Scales
- Natural minor or minor pentatonic
- Progressions
- i-VII-VI-VII or i-VI-III-VII
- Arrangement
- low register, pedal tones, sparse upper harmony
Dramatic and inevitable
- Scales
- Harmonic minor
- Progressions
- i-iv-V-i or i-VII-VI-V
- Arrangement
- strong leading tone, rising sequence, decisive cadence
Hopeful minor
- Scales
- Dorian
- Progressions
- i-IV or i-ii-IV-i
- Arrangement
- feature natural 6, upward melody, active groove
Weightless and luminous
- Scales
- Lydian, major pentatonic or whole tone
- Progressions
- I-II or slow major-seventh planing
- Arrangement
- wide voicings, high register, weak cadences
Tense and compressed
- Scales
- Phrygian, Locrian fragments or chromatic collection
- Progressions
- i-flat II or diminished pedal harmony
- Arrangement
- small intervals, repeated ostinato, narrow register
Playful and quirky
- Scales
- Mixolydian, pentatonic or chromatic neighbor tones
- Progressions
- I-flat VII-IV with abrupt secondary dominants
- Arrangement
- syncopation, short articulations, register jumps
Dreamlike and unresolved
- Scales
- Whole tone, Lydian or ambiguous pentatonic
- Progressions
- augmented planing or Imaj7-II over tonic pedal
- Arrangement
- slow attack, blurred pulse, nonfunctional motion
Bluesy and resilient
- Scales
- Blues or minor pentatonic over dominant harmony
- Progressions
- 12-bar blues variants
- Arrangement
- bent thirds, call and response, shuffle or backbeat
Futuristic and unstable
- Scales
- Altered, diminished or chromatic
- Progressions
- dominant chains, tritone substitutions, symmetric sequences
- Arrangement
- precise rhythm, synthetic timbre, sudden tonal pivots
Melody and chord-scale connection
Make strong beats explain the harmony
Chord-scale theory connects a chord’s tones and available extensions to a scale, but it does not mean the key changes on every chord. Keep the larger key center and phrase direction audible while using chord tones to clarify local harmony.
Start with chord tones
Place root, third, fifth or seventh on strong beats so the melody states the harmony.
Use non-chord tones with direction
Passing notes connect chord tones, neighbors leave and return, suspensions delay a chord tone and appoggiaturas lean into resolution.
Build a motif
Choose a short interval-and-rhythm cell, repeat it, sequence it and alter its ending.
Control contour
Save the highest note, widest leap or longest duration for an important word or structural peak.
Write the rhythm first
A single pitch with a strong phrase rhythm can reveal where the melodic notes should go.
Target guide tones
Thirds and sevenths define chord quality and move efficiently through many progressions.
Use range as form
Keep verses narrow and lower, then widen or raise the chorus.
Leave negative space
Rests create breath, groove and room for instrumental response.
From theory to sound
Apply the same relationships on different tools
Guitar songwriter
Choose a comfortable key or capo position, loop two to four chords, sing scale degrees over them, then improve bass motion with inversions or slash chords.
Keyboard songwriter
Play shell voicings in the left hand and melody in the right, preserve common tones, then add sevenths or ninths only where they clarify color.
DAW producer
Set key and scale assistance, sequence a bass root pattern, voice chords across separate registers, then derive melody from chord tones and characteristic scale notes.
MIDI arranger
Duplicate the chord track, reduce one copy to roots for bass, spread another into inversions, and extract selected chord tones for countermelody.
Loop-based producer
Treat the loop as a tonal claim, identify its bass and strongest pitches, then choose a compatible tonic before adding new chords.
Singer-first writer
Find the vocal center and highest comfortable note first, choose a key that protects the chorus peak, then harmonize the melody rather than forcing it into a preset loop.
Practice path
Build from hearing to analysis
- Hear and name scale degrees 1 through 7 in major and minor.
- Build major, minor, diminished and augmented triads from intervals.
- Learn diatonic triads and seventh chords in several keys.
- Write short progressions using tonic, predominant and dominant functions.
- Practice inversions and common-tone voice leading.
- Compare parallel modes by changing one characteristic degree.
- Add one borrowed chord or secondary dominant to a diatonic progression.
- Write a melody using chord tones on strong beats and non-chord tones between them.
- Rebuild the same progression for guitar, keyboard and MIDI to learn voicing rather than shapes alone.
- Analyze finished songs by key center, Roman numerals, harmonic rhythm, cadence, form and melodic contour.
Sources
Study the underlying concepts
This guide synthesizes standard theory concepts into practical songwriting and production workflows. Follow these open educational references for notation, analysis and deeper examples.
Common questions
Short answers
Do I need to read notation to use this guide?
No. The formulas, note names, Roman numerals, fretboard-oriented ideas and MIDI workflows can be used without staff notation. Notation remains useful when communicating exact rhythm, register and voice leading.
Are major scales always happy and minor scales always sad?
No. Major and minor establish interval and harmonic relationships, not fixed emotions. Tempo, groove, register, voicing, melody, dynamics and timbre can reverse the expected impression.
What is the difference between chord symbols and Roman numerals?
A chord symbol names exact pitches, such as Dm7. A Roman numeral names a chord’s relationship to the key, such as ii7, so the same function can be moved to another key.
How should a guitarist start using Roman numerals?
Choose a familiar chord loop, identify the key, label each chord by scale degree, then move the same numerals to a new key or capo position.
How should a DAW producer apply scales?
Set a tonal center, constrain MIDI notes to a scale, build bass and chords from scale degrees, and emphasize chord tones on strong beats. Use out-of-scale notes deliberately as approaches, borrowed colors or modulation.
How do I choose a scale for a chord progression?
Begin with the parent key when the chords are diatonic. For modal or chromatic harmony, identify the tonic, chord qualities and characteristic notes, then select a scale that supports those tones without erasing the progression’s function.
Can I hear and download the chord progressions?
Yes. The progression tool can synthesize a preview in the browser, download the selected sound as a WAV file and export editable MIDI for a DAW. No recording or musical choice is uploaded to a server.