Key

The Key panel lays out the selected key in full: its scale, the chord built on each of its seven degrees, what each degree is called, and the keys related to it.

The top row

Tonic

The note button opens a grid of all seven letters, each as flat, natural or sharp, so you can choose F♯ or G♭, C♯ or D♭. The key you pick is spelled from that note.

Mode

Nine scales, in this order: major; natural minor, harmonic minor and melodic minor; then the modes dorian, phrygian, lydian, mixolydian and locrian.

Volume

The slider sets the volume for every play button in the app. On iPhone it sits on its own line under the menus.

Triads / 7ths

Switches the chord row between three-note chords and four-note seventh chords. The setting also decides which chords the Progressions panel's Add row offers.

The scale row

The seven notes of the scale, spelled correctly for the key, with each note's step underneath: 1 2 3 4 5 6 7 for major, and 1 2 ♭3 4 5 ♭6 ♭7 for natural minor. The tonic is blue. Tap any note to hear it.

Each scale uses every letter once. That is what makes F♯ major end on E♯ rather than F, and it is how a key signature works on paper.

The chord row

One card for each degree of the scale, left to right from the tonic. Each card stacks five things:

Roman numeral

Upper case for a major chord, lower case for minor, ° for diminished and + for augmented. The color follows the chord's quality: teal for major, orange for minor.

Chord symbol

Drawn in the notation style you chose in Settings: E♭Δ7 in jazz, E♭maj7 in plain text, or spelled out.

Scale step

Which note of the scale the chord is built on, matching the scale row above.

Stacked thirds

The chord read as the thirds it is built from, one letter per gap: M major third, m minor third, d diminished, A augmented. A major triad is Mm, a major seventh MmM, a diminished triad mm.

Degree name

Tonic, supertonic, mediant, subdominant, dominant, submediant, and for the seventh either leading tone or subtonic.

Tap a card to make that chord the current chord everywhere and to hear it. The card for the current chord is outlined.

Leading tone or subtonic

The seventh degree is the leading tone only when it sits a semitone below the tonic and pulls up to it, as it does in major and harmonic minor. When it sits a whole tone below, in natural minor and the flat-seventh modes, it is the subtonic. The card says which.

The footer

Relative and Parallel

The relative key shares this key's notes and signature (C major and A minor). The parallel key shares its tonic (C major and C minor). Tap either name to jump there.

Signature

At the right, how many sharps or flats the key carries: "3 flats", "No sharps or flats".

Pentatonic and blues

The five-note pentatonic and six-note blues scales built on the same tonic, major forms for a major-sounding key and minor forms for a minor one. Tap any note to hear it.

How it works

Every chord on the row is built only from the scale's own notes: start on a degree, then take every other note above it. That is why the qualities fall into a pattern. In any major key it is always major, minor, minor, major, major, minor, diminished; in natural minor it is the same pattern started from the sixth. The numerals let you talk about chords without naming a key, so "ii, V, I" means the same thing in every key.

With the other panels

The key you set here is the same key the Circle of fifths lights, and it decides which notes the Piano and Guitar color as belonging. Starter progressions follow it. Tapping a chord card sets the chord the Chord, Notation, Piano and Guitar panels all show.