Bb Whole-Half Diminished Scale
The Bb whole-half diminished scale (also written A#) — Bb C Db Eb E Gb G A — with its intervals, the chords it fits and every position on the guitar neck.
Also written A# whole-half diminished. A# and Bb are the same pitch — Bb is the spelling in common use.
Tap any note on the neck.
Swipe the neck sideways to see the higher frets.
Bb whole-half diminished scale notes and intervals
Bb whole-half diminished has 8 notes. Each is named by its distance from the root, which is the same in every key — learn the numbers once and every whole-half diminished scale reads the same.
Step pattern from the root: W – H – W – H – W – H – W – H (W is a whole step, two frets; H is a half step, one fret).
Scales it shares notes with:
- C half-whole diminished — half-whole diminished — the same eight notes from the 2
- C# whole-half diminished — whole-half diminished from the b3 — the same eight notes again, a minor third up
Bb whole-half diminished scale positions on guitar — all 8
Three notes on every string gives Bb whole-half diminished eight positions, one starting on each note of the scale, that together cover frets 0 to 15. The scale repeats itself every minor third, so the eight are only two shapes: positions 1, 3, 5 and 7 are one, 2, 4, 6 and 8 the other, and moving either one three frets up or down gives the same notes again. Learn the two and slide them.
Position 1 — frets 5–9
Starts on the 1 (Bb) on the 6th string. Practice this position →
Position 2 — frets 6–11
Starts on the 2 (C) on the 6th string. Practice this position →
Position 3 — frets 8–12
Starts on the b3 (Db) on the 6th string. Practice this position →
Position 4 — frets 9–14
Starts on the 4 (Eb) on the 6th string. Practice this position →
Position 5 — frets 11–15
Starts on the b5 (E) on the 6th string. Practice this position →
Position 6 — frets 0–5
Starts on the b6 (Gb) on the 6th string. Practice this position →
Position 7 — frets 2–6
Starts on the 6 (G) on the 6th string. Practice this position →
Position 8 — frets 3–8
Starts on the 7 (A) on the 6th string. Practice this position →
Chords to play Bb whole-half diminished over
Bb whole-half diminished is the scale for the diminished 7th chord Bbdim7 (Bb Db E G). It puts a note a whole step above each chord tone (C Eb Gb A). A diminished 7th repeats every minor third, and so does the scale: the same eight notes fit the chord whichever of its four notes is in the bass.
Play the Bbdim7 arpeggio inside the scale → The Practice Loop keeps only the chord’s notes in each position, so you hear what the rest of the scale is decorating.
How to practice the Bb whole-half diminished scale
- Start with position 6 at frets 0–5, slowly, until every note lands on the click. The loop keeps the shape and the tempo for you.
- Slide the shape: position 8 is the same fingering 3 frets higher, and the same notes. Play one, then the other, and the move is the scale.
- Climb 4 notes at a time, two notes up each time: each group starts a minor third above the last, the same step the scale repeats by.
- Switch the same position to the Bbdim7 arpeggio, the chord’s notes alone, then back to the scale.
- See every Bb whole-half diminished note across the whole neck on the Fretboard, and find each box again an octave up.
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