Chord & FretBb/A — with the major seventh in the bass
Also written A#/A — the same chord, spelled the other way.
Notes in Bb/A: A – Bb – D – FFormula: 1 – 3 – 5 / 7In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
The bass falls from C to B while the chord stays put — in practice, a maj7 with the seventh underneath. It is the second step of the descent C → C/B → AmAmAmAm → C/G.
The same chord on all four instruments
Where to use it: Descending bass lines in ballads and fingerpicked accompaniment.
The shapes of Bb/A don't end on this page — the whole neck holds dozens. In Chord & Fret, you hear every shape strummed string by string, in each instrument's own voice; compare positions with their difficulty marked; and change the tuning — the shape rewrites itself. Start free. Unlock everything with Pro. Plays offline.
See the whole neck in Chord & Fret →Part of the Inversions (slash) family.