CadenzaB♭ dominant thirteenth
B♭13
Also written A♯13 · B♭7(13) · B♭dom13
The dominant 13th: 1–3–♭7–9–13, with the 5th and the 11th usually left out. V of E♭ major. In a rootless voicing the 13th (G) stands where the 5th would be — that one note is the whole difference between B♭9 and B♭13.
How pianists voice B♭13
Nobody plays a jazz chord in root position. These are the shapes that actually get played — the same ones Cadenza shows when you play the chord.
Shell Left hand
1 · 3 · ♭7 — root, 3rd and 7th: the three notes that say what the chord is. Left hand, low; everything else is colour.
Rootless A From the 3rd
3 · 13 · ♭7 · 9 — no root: the bass player has it. The left-hand voicing of modern jazz piano.
Rootless B From the 7th
♭7 · 9 · 3 · 13 — the other half of the pair. A and B alternate through a ii–V–I so the hand barely moves. Without B♭ underneath, the same keys read as A♭maj7(♯11) — the bass turns them into B♭13.
Drop 2 Two hands
13 · 1 · 3 · ♭7 — close position with the second voice from the top dropped an octave: wider, warmer, the standard for chord melody.
Dominant thirteenth chords in every key
Every B♭ chord
Play a chord. See its name.
The free chord finder names whatever you play — on a MIDI keyboard, with your mouse or on your computer keys — with the same engine as Cadenza.
Or let the app follow you.
Cadenza names every chord you play, live, writes what you played as sheet music, and puts the keyboard straight into OBS. The core is free forever.