Intervallic Jazz Melodies

Intervallic improvisation

Build a line from successive intervals

The generator measures each interval from the previous note. Choose a starting note, cell, order and direction, then verify the line by listening, OSMD notation and MIDI export.

Generate a useful line

Choose a starting note and register.
Select two or three intervals with the circle.
Try rotations, permutations or mirrored directions.
Listen, read the notation and export only lines that make musical sense.

Intervallic improvisation

Understand Cells, Contour and Transposition

Successive intervals

Each leap starts from the previous note: +3 then +7 is not two distances from the tonic, but a cumulative melodic line.

Transformations

A rotation changes the starting point; a permutation changes the order; directional inversion flips signs without becoming a chord inversion.

Modern jazz use

Outside notes may be intentional. Judge the line by contour, resolution, rhythmic placement and harmonic context.

Practice method

Sing the contour before playing it.
Keep the cell short before widening the register.
Transpose one line through at least three keys.
Over ii-V-I, check where the line creates tension and resolution.

Melodic interval, cell and contour

Example

A melodic interval connects two successive notes. A cell is a short interval sequence that can be repeated, rotated, inverted or transposed.

The generator mainly works with semitone magnitude. Enharmonic names such as minor third and augmented second can share three semitones while carrying different theoretical functions.

Verified transformation examples

Example

These examples follow the engine’s cumulative logic: each signed value starts from the previous note, and transposition preserves the semitone structure.

Concept	Cell	Result
Successive intervals	+3, +7, -2 from C4	C4 -> Eb4 -> Bb4 -> Ab4
Rotation	+3, +7, -2	+7, -2, +3
Directional inversion	+3, +7, -2	-3, -7, +2
Transposition	C4 -> Eb4 -> Bb4 -> Ab4, +2 semitones	D4 -> F4 -> C5 -> Bb4

Harmony, outside notes and resolution

ii-V-I

An intervallic line does not have to remain strictly inside the scale to be musical. In jazz, an outside note can create tension, color or direction when resolution and rhythm are clear.

Over Dm7-G7-Cmaj7, target thirds and sevenths as arrival points, then let wide leaps fill the space between them.

Rhythm, duration and export

MIDI

At quarter-note tempo, one quarter lasts 60 / BPM seconds. The selected note length defines the events sent to playback, MusicXML and MIDI.

Export chromatic or outside lines too when they serve a musical idea; strict key membership is not a condition for validity.

Ten progressive exercises

Each exercise starts from a short cell, then adds a contour, rhythm, transposition or harmonic constraint.

Objective	Start	Cell	Instruction
Contour	C4	+3, -2	Sing the shape, then play it slowly.
Two-interval cell	D4	+5, -3	Repeat until the contour is audible without the screen.
Three-interval melody	C4	+3, +7, -2	Generate one line and name every note.
Ascending/descending	F4	+4, +5	Compare all-up and all-down versions.
Rotation	C4	+3, +7, -2	Play each rotation and keep the most singable.
Permutation	G3	+2, +5, +7	Change order, then check whether the phrase still resolves.
Mirrored motion	C4	+3, +7	Invert direction and listen for register balance.
Transposition	C4	+3, +7, -2	Move the line through C, D, F and Ab.
ii-V-I phrasing	D4	+3, +5, -2	Aim arrivals at guide tones over Dm7-G7-Cmaj7.
Composition	Any	Your own cell	Develop the cell with rhythm, silence and repetition.