Map it slowly
Locate A, C on white keys and E♭, G♭ on black keys. Try each hand separately before playing together; choose a fingering that keeps the wrist relaxed, without stretching between notes.
Arpeggio · A°7 · Piano
The A°7 arpeggio is A – C – E♭ – G♭ — chord tones 1 ♭3 ♭5 𝄫7. A°7 is passing chords between diatonic chords, and as a 7♭9 without its root; its sound is symmetrical, restless. Below, every A, C, E♭, G♭ on the two-octave keyboard is marked, with the root in gold. Press play to hear a one-octave arpeggio, or tap any note.
Visualizer
Piano
Guitar · standard tuning
Play loops the arpeggio up and down one octave (switch Loop off for a single pass). Tap any marked note to hear it. “Show” switches or combines the fretboard and keyboard; “Sound” picks the instrument you hear. Audio is synthesized in the browser.
Your next 10 minutes
Locate A, C on white keys and E♭, G♭ on black keys. Try each hand separately before playing together; choose a fingering that keeps the wrist relaxed, without stretching between notes.
Play A – C – E♭ – G♭ in quarter notes at 60 bpm. Repeat starting from C, wrapping back to A. Do not speed up until every attack is even.
Alternate C and G♭ above a sustained A. These are degree ♭3 and 𝄫7. End a four-bar phrase on either one instead of always returning to the root.
Listen for this: A°7 has the colour “symmetrical, restless”. Name the degrees as you play, so you can recognize the sound in another key rather than remembering only a shape.
Understand the sound
Successive chord tones are separated by minor thirds. The seventh is a diminished seventh, not a major sixth in the chord’s theoretical spelling, even when they share a piano key.
Here the third is C, and degree 𝄫7 is G♭. Play A in the bass and compare these voices individually before combining them.
Try C – E♭ – G♭ – A as quarter notes, then repeat the first note and omit the last. The second phrase uses the same harmony with a different shape.
Separate the bass from the upper notes. If the low register sounds muddy, move the upper voices up an octave before adding more notes.
The black-key pitches in this collection are E♭, G♭. Use the groups of two and three black keys to orient yourself. Play A and C with each hand separately before combining the hands.
Before moving on, close the diagram and name the notes: A · C · E♭ · G♭. Then play a two-bar phrase from memory and leave two bars of silence.
On guitar
Reference
| Chord tone | Note | Interval from A |
|---|---|---|
| 1 | A | unison (0 semitones) |
| ♭3 | C | minor 3rd (3 semitones) |
| ♭5 | E♭ | diminished 5th (6 semitones) |
| 𝄫7 | G♭ | diminished 7th (9 semitones) |
Goes with: A Diminished (whole–half) (A B C D E♭ F G♭ A♭). Voicings: A°7 voicings on piano.
Take it to the bandstand.Practice Radio streams endless changes to play the A°7 arpeggio over through all twelve keys, with the chord and scale shown live — plus ear-training and call & response modes.
▶ Open Practice RadioCommon questions
A – C – E♭ – G♭. As chord tones: 1 ♭3 ♭5 𝄫7. Played one after another instead of together, that is the arpeggio.
A°7 is passing chords between diatonic chords, and as a 7♭9 without its root. Its character is symmetrical, restless.
A Dim. W–H (A B C D E♭ F G♭ A♭) — the arpeggio is the skeleton of that scale, so practise them together.
Play A – C – E♭ – G♭ ascending from A, then descend; then start from each chord tone in turn (inversions) so your hand knows the shape from any note.
Keep going
Same arpeggio on guitar · Diminished 7th hub · chord-scale theory.
Other arpeggios from A