Bb13 — dominant thirteenth
Also written A#13 — the same chord, spelled the other way.
Notes in Bb13: Bb – D – F – Ab – C – GFormula: 1 – 3 – 5 – b7 – 9 – 13In 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 13 is the full extended dominant. In practice, the third and seventh define the function while the thirteenth gives the color — the root and fifth can be omitted.
The same chord on all four instruments
Where to use it: An elegant dominant in jazz, MPB and gospel.
Every region of the neck hides more shapes of Bb13. In Chord & Fret, you check it note by note, playing any shape as an arpeggio; open every variation on the neck, grouped by bass note; and set a capo — the diagrams redraw above it. Start free. Unlock everything with Pro. Plays offline.
See the whole neck in Chord & Fret →Part of the Extended family.