Learn to Play B Altered Dominant
What notes are in b altered dominant?
The b altered dominant chord (B7b9) is built from the notes B, D#, A, C — root, major 3rd, minor 7th, ♭9.
B7b9
A dominant 7 with altered extensions: ♭9, ♯9, ♭5/♯11 or ♯5 in place of the natural tensions. The 3rd and ♭7 stay put — the frame holds while the paint melts.
Variants
B7#9: B – D# – A – D
B7#5: B – D# – G – A
B7b5: B – D# – F – A
How does b altered dominant sound?
Controlled chaos — a dominant with its 5th and/or 9th bent out of shape. Alt chords snarl, smear and then resolve like nothing happened.
Maximum-tension dominants: every altered note is a half step from a note of the target chord, so V7alt → I resolves with every voice sliding one semitone. Tension buys smoothness.
Where do you use B7b9?
Play a B altered dominant as the V of E when the resolution needs drama: every altered note sits a half step from a E chord tone, so the snarl melts into place.
B reads as five sharps and scares people off the page — but the hand position is genuinely comfortable; Chopin liked starting students here for exactly that reason.
Bebop and post-bop turnarounds, the ♯9 IS the Hendrix chord ("Purple Haze"), gospel preachers' final V, and any ii–V that wants drama before the payoff.
How do you finger B7b9 on piano?
Most alt voicings are four-note grips (3rd-♭7 core + two alterations): 1-2-3-5 with the alterations on 2 and 5, keeping the defining tritone anchored under 1 and 3.
1 of the 4 keys here is black — play those with the longer fingers and keep the wrist level.
Tip: the common mistake
Altering the wrong notes. The 3rd and ♭7 NEVER alter — they define the dominant. If those move, the chord stops functioning; only 5ths and 9ths bend.
Reading about B Altered Dominant is step one — recognizing it at speed is the game. Chord Rush drills it until your hands know it.
- ⚡Speed
- ◎Accuracy
- ♪Recognition