Chord · B Dominant 7♯9 (Hendrix)
B7♯9 Chord
B7♯9 is B, D#, F#, A and C## — the Hendrix chord. Bluesy and aggressive.
B7♯9 on every instrument
The same 5 notes, 2 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What B7♯9 is made of
B Dominant 7♯9 (Hendrix) (B dominant 7♯9 (hendrix)) is built from the notes B, D#, F#, A, C##, with the interval pattern 1, 3, 5, b7, #9. A common dominant 7♯9 (hendrix) chord across many styles.
Stack 1, 3, 5, b7 and #9 on a root of B and you get B, D#, F#, A and C##. That interval recipe is what makes the chord a seventh sharp nine chord — move the same shape to another root and the character travels with it, which is why C7♯9 sounds like a transposed B7♯9.
Dominant 7♯9 (Hendrix): The Hendrix chord. Bluesy and aggressive.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with D♯ rather than its enharmonic equivalent.
Keys that contain B7♯9
No major or natural-minor key contains all 5 of these notes — this one gets borrowed.
Chords like this one sit outside the diatonic set — they arrive as secondary dominants, borrowed chords or passing harmony. Browse every key to see which progressions pull it in.
Other chords on B
Same root, different colour.
The same seventh sharp nine shape, moved
The identical interval recipe, built on other roots.
Questions people ask about B7#9
- What notes are in the B7#9 chord?
- B7#9 is made of B, D#, F#, A and C## — the 1, 3, 5, b7 and #9 degrees of a seventh sharp nine chord built on B.
- What keys use the B7#9 chord?
- No major or natural-minor key contains all 5 notes of B7#9. Chords like this arrive as borrowed harmony — secondary dominants, harmonic-minor colour, or chromatic passing chords — rather than as one of a key's native chords.
- How do you play B7#9 on guitar and piano?
- This page shows B7#9 on guitar and piano — 5 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why B7♯9 behaves the way it does — the guides that explain the chord instead of just spelling it.