Map it slowly
Locate E on white keys and A♯, C♯, 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♯m7♭5 · Piano
The A♯m7♭5 arpeggio is A♯ – C♯ – E – G♯ — chord tones 1 ♭3 ♭5 ♭7. A♯m7♭5 is the iiø chord of a minor ii–V–i; its sound is dark, unstable, leading. 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 E on white keys and A♯, C♯, 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♯m7♭5 has the colour “dark, unstable, leading”. Name the degrees as you play, so you can recognize the sound in another key rather than remembering only a shape.
Understand the sound
Compare the flat fifth with a perfect fifth while keeping the other notes fixed. That one change turns a minor seventh into a half-diminished chord.
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 A♯, C♯, 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♯ | minor 7th (10 semitones) |
Goes with: A♯ Locrian (A♯ B C♯ D♯ E F♯ G♯). Voicings: A♯m7♭5 voicings on piano.
Take it to the bandstand.Practice Radio streams endless changes to play the A♯m7♭5 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♯m7♭5 is the iiø chord of a minor ii–V–i. Its character is dark, unstable, leading.
A♯ Locrian (A♯ B C♯ D♯ E F♯ G♯) — 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 · Half-diminished (m7♭5) hub · chord-scale theory.
Other arpeggios from A♯