Scale Finder

A scale is a short list of pitches taken from a root, and this tool shows the list in four ways at once: as the note names it is written with, as the formula that produces it, as the pattern of whole and half steps that sounds it, and, for seven-note scales, as the chords built on each of its notes. The fourth view is the one most people use the scale for, so the chords are shown in full.

#A scale is a formula on a root

Every scale type in the tool is stored as a formula measured in scale degrees. Major is 1 2 3 4 5 6 7. Dorian is 1 2 ♭3 4 5 6 ♭7, which means the root, the second, a minor third, the fourth, the fifth, the sixth and a minor seventh. Spelling the formula on a root gives the notes. On D, the dorian formula gives D, E, F, G, A, B and C, and the tool writes exactly those letter names.

Because the formula is measured from the root, the same scale can start on any note. The root menu offers the twelve common spellings and the type menu offers 21 types. Each combination is spelled out with its own notes, pattern and chords. A link to a reference page appears only for the combinations that have one, which excludes the awkward spellings that need double sharps or flats in a common key.

#The step pattern is what you hear

The steps are worked out from the pitches, not from the formula. The tool measures the gap between each note and the next, ending at the octave, and writes each gap as W for a whole step (two semitones), H for a half step (one semitone), or W+H for a minor third. The major scale is W W H W W W H. Dorian from D is W H W W W H W. Harmonic minor is W H W W H W+H H. The W+H between the sixth and the seventh degree is the gap that gives that scale its character.

The pattern is a fingerprint. Two scales with the same letter names can have different patterns, and two with different letter names can share one. Learning the pattern lets you play a scale from any root by starting the same sequence of steps, which is quicker than memorising each key.

#Modes are rotations of one scale

The seven modes come from the major scale, played from each of its degrees. Starting on the second note gives dorian, on the third phrygian, on the fourth lydian, on the fifth mixolydian, on the sixth the natural minor (aeolian) and on the seventh locrian. The notes are the same, and only the tonic moves. That is why dorian from D has no sharps or flats: it is the white keys, and its pattern is the major pattern started from the second degree.

Modes sound different because the tonic is different. The gaps around the tonic decide which note feels like home, and the tool shows that as the step pattern. Compare D dorian with C major: the notes are identical, but the pattern and the chord list both differ.

#Why the spelling matters

A seven-note scale uses each letter name once. In F♯ harmonic minor the seventh degree is E♯, not F, because F would mean the letter F appears twice in the same scale, once as F♯ and once as F. Each degree keeps its own letter, so a reader can find it on the staff without counting lines. The tool keeps this rule for every seven-note type. Eight-note scales such as the diminished scales repeat letters by necessity, and the list shows the repeats as they are.

Enharmonic names are not the same notation. A scale spelled with double sharps may sound identical to a simpler one, but it is harder to read, and the tool chooses the spelling a reference page would print.

#Pentatonic and blues scales

Pentatonic scales have five notes and no half steps. The major pentatonic is 1 2 3 5 6, which is the major scale with the fourth and seventh removed. The minor pentatonic is 1 ♭3 4 5 ♭7, the minor scale with the second and sixth removed. Because no two neighbouring notes are a half step apart, the notes sit comfortably over many different chords.

The blues scale is the minor pentatonic with one note added, the flat fifth. That note creates two half steps in the scale, and it is the source of the blue note. It is written as ♭5 on the page, which the tool shows in the formula and the step pattern.

#Using the chord list

For each seven-note scale the tool stacks a seventh on every degree, using only the notes of that scale. The result is the set of chords the scale supports without changing a note. D dorian gives Dm7, Em7, Fmaj7, G7, Am7, Bm7♭5 and Cmaj7. The first chord is built on the tonic, and the rest follow from the same notes.

Compare the list with the chords of C major, which use the same letters. The tonic chord changes from Cmaj7 to Dm7, and the other chords move with it. Play a progression in one scale, then play the same degrees in the other, and the difference of tonic becomes audible. Each chord button plays the seventh as a block below middle C, so the difference in colour is easy to hear.

#Which scales fit

Select the notes you have, and the tool lists every common root and scale type that contains all of them, with the fewest notes first. C, D, E, G and A give C major pentatonic first, then A minor pentatonic and A blues, then the seven-note scales that contain all five notes. Opening a result switches to Show a scale with that root and type, so the notes and chords can be checked.

#Limits

The tool shows the 21 scale and mode types in the reference tables, spelled in equal temperament. It does not show microtonal scales, scales from other traditions with quarter tones, or chords built on degrees other than sevenths. Sevenths are shown only for seven-note scales, since a stack of thirds needs one note per degree. The tool does not record, save or export anything.