About this tool
Look up the notes of any scale and the chords that come from it, right in your browser. Choose a root note and a scale or mode — major, natural minor, the church modes, harmonic and melodic minor, major and minor pentatonic, or blues — and it lists the notes, their scale degrees and, for seven-note scales, the diatonic triads with roman numerals. Everything is computed locally.
Each scale is defined by a pattern of semitone steps, for example major is [2, 2, 1, 2, 2, 2, 1]. A running (cumulative) sum of those steps, taken modulo 12 from the root, gives the pitch class of each note, which is then spelled to the key using proper letter names so every degree gets its own letter. The diatonic chords are built by stacking thirds within the scale and are labelled major, minor, diminished or augmented from the intervals between the stacked notes.
For example, C major returns C D E F G A B with chords I ii iii IV V vi vii°. Use it to learn a key's notes, find the chords that fit a progression, or explore modes and pentatonic shapes for improvising.