akousia
Start here

C#add9 Chord

C#add9 keeps the C sharp major triad and adds D sharp, its ninth. The major third remains, so this is different from a sus2 chord, which replaces the third.

  • Notes: C sharp-E sharp-G sharp-D sharp
  • Symbol: C#add9
  • Iadd9 in C# major
  • Added ninth
Switch chordC#add9

How to play a C#add9 chord

Notes: C# - E# - G# - D# · symbol C#add9

  • Root position

    C# - E# - G# - D#
    C4C5
    Right hand 1-2-3-5 · Left 5-3-2-1

  • 1st inversion

    E# - G# - D# - C#
    C4C5
    Right hand 1-2-3-5 · Left 5-4-2-1

  • 2nd inversion

    G# - D# - C# - E#
    C4C5
    Right hand 1-2-4-5 · Left 5-3-2-1

  • 3rd inversion

    D# - C# - E# - G#
    C4C5
    Right hand 1-2-4-5 · Left 5-3-2-1

Where does C#add9 belong?

The ninth adds color to an otherwise familiar major chord without replacing its third.
Play the role cards to hear how its surrounding chords change the job it does; Diatonic Chords explains the basic numbered roles.

  • In C# majorHome with shimmer
    Iadd9

    The ninth sits on top of a plain major chord, without a seventh.

    F#IVG#VC#add9Iadd9
  • In Ab majorBright step away
    IVadd9

    The IV of Ab major with an added ninth. In this key the chord is spelled Dbadd9.

    AbIDbadd9IVadd9EbVAbI

Progressions to try

  • F#G#C#add9

    C#add9 is the tonic arrival; the added ninth remains above the familiar major triad.

  • AbDbadd9EbAb

    Here the added ninth colors the IV chord while the loop still ends on the ordinary tonic. Here the same sounding chord is written Dbadd9 rather than C#add9.

Which shape should you use?

On guitar, start with x43141, a barre at the 1st fret.

On ukulele, start with 1314, played at the 1st fret. 6546 gives a higher version.

On piano, play C sharp-E sharp-G sharp-D sharp. Move C sharp up an octave to reach the first inversion, E sharp-G sharp-D sharp-C sharp; the notes remain the same while the lowest voice changes.

What are the inversions?

C sharp, E sharp and G sharp make the major triad; D sharp adds the ninth, an octave plus a second above the root.

  • Root position: C sharp-E sharp-G sharp-D sharp, with C sharp lowest.
  • First inversion: E sharp-G sharp-D sharp-C sharp, written C#add9/E# if E sharp is lowest in the whole arrangement.
  • Second inversion: G sharp-D sharp-C sharp-E sharp, written C#add9/G# if G sharp is lowest in the whole arrangement.
  • Third inversion: D sharp-C sharp-E sharp-G sharp, written C#add9/D# if D sharp is lowest in the whole arrangement.

A slash chord names the note in the bass, not merely the lowest note under one hand. Chord Inversions shows how to read that distinction.

How does C#add9 differ from C#9?

C#add9 has the third and ninth but no seventh. Add B and you get C#9; the comparer lets you hear what that extra seventh changes. Try that one-note change on piano, then use the comparer to hear it in the full chord. See C#9 for the other chord's full spelling and roles.

  • C#add9

    C# - E# - G# - D#
    C4C5

    C# add9

  • C#9

    C# - E# - G# - B - D#
    C4C5

    C# dominant 9

Try another chord