Map it slowly
Locate B, D, F, A on white keys. Try each hand separately before playing together; choose a fingering that keeps the wrist relaxed, without stretching between notes.
Arpeggio · Bm7♭5 · Piano
The Bm7♭5 arpeggio is B – D – F – A — chord tones 1 ♭3 ♭5 ♭7. Bm7♭5 is the iiø chord of a minor ii–V–i; its sound is dark, unstable, leading. Below, every B, D, F, A 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 B, D, F, A on white keys. Try each hand separately before playing together; choose a fingering that keeps the wrist relaxed, without stretching between notes.
Play B – D – F – A in quarter notes at 60 bpm. Repeat starting from D, wrapping back to B. Do not speed up until every attack is even.
Alternate D and A above a sustained B. These are degree ♭3 and ♭7. End a four-bar phrase on either one instead of always returning to the root.
Listen for this: Bm7♭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 D, and degree ♭7 is A. Play B in the bass and compare these voices individually before combining them.
Try D – F – A – B 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 none. Use the groups of two and three black keys to orient yourself. Play B and D with each hand separately before combining the hands.
Before moving on, close the diagram and name the notes: B · D · F · A. Then play a two-bar phrase from memory and leave two bars of silence.
On guitar
Reference
| Chord tone | Note | Interval from B |
|---|---|---|
| 1 | B | unison (0 semitones) |
| ♭3 | D | minor 3rd (3 semitones) |
| ♭5 | F | diminished 5th (6 semitones) |
| ♭7 | A | minor 7th (10 semitones) |
Goes with: B Locrian (B C D E F G A). Voicings: Bm7♭5 voicings on piano.
Take it to the bandstand.Practice Radio streams endless changes to play the Bm7♭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
B – D – F – A. As chord tones: 1 ♭3 ♭5 ♭7. Played one after another instead of together, that is the arpeggio.
Bm7♭5 is the iiø chord of a minor ii–V–i. Its character is dark, unstable, leading.
B Locrian (B C D E F G A) — the arpeggio is the skeleton of that scale, so practise them together.
Play B – D – F – A ascending from B, 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 B