How do you play the C 7(#9)/A chord?

To play the C 7(#9)/A chord on piano, play the C 7(#9) chord (C, E, G, A# and D#) with A as the lowest bass note. Place the A note below the other chord tones. Slash chords specify a particular bass note different from the chord root.

What is a slash chord?

A slash chord (or compound chord) is written as Chord/Bass and specifies both a chord and a bass note. The note to the right of the slash is played as the lowest note. The C 7(#9)/A chord means a C 7(#9) chord with A in the bass.

C 7(#9)/A

Q: What notes are in the C 7(#9)/A chord?

The C 7(#9)/A chord uses the 5 notes of the C 7(#9) chord — C (Perfect unison), E (Major third), G (Perfect fifth), A# (Minor seventh) and D# (Minor tenth) — with A played as the bass note in the lowest register.

The C 7(#9) chord consists of the C (Perfect unison), E (Major third), G (Perfect fifth), A# (Minor seventh) and D# (Minor tenth) notes, with A as the bass note.

Piano keyboard showing the notes for a C 7(#9)/A chord

How to play the C 7(#9)/A chord

Play A as the lowest bass note in the left hand
Find C (Root) on the piano keyboard
Add E (Major third) — 4 semitones above C
Add G (Perfect fifth) — 7 semitones above C
Add A# (Minor seventh) — 10 semitones above C
Add D# (Minor tenth) — 15 semitones above C
Press all 6 notes simultaneously to sound the C 7(#9)/A chord