Chord & FretBb7(b13) — dominant flat thirteenth
Also written A#7(b13) — the same chord, spelled the other way.
Notes in Bb7(b13): Bb – D – F – Ab – GbFormula: 1 – 3 – 5 – b7 – b13In 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 7(b13) is a dark dominant, with the thirteenth lowered. The tension pulls strongly toward resolution.
The same chord on all four instruments
Where to use it: A dark resolution, especially to a minor chord.
This is just one shape of Bb7(b13). In Chord & Fret, you check it note by note, playing any shape as an arpeggio; 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 Altered dominants family.