The root left to the bass player. Frees a finger for a tension.
C#m9 is C#, E, G#, B and D# — C#m7 with the ninth stacked above it.
It sounds warm, and considerably richer than an m7. The standard voicing for a ii chord once the plain one has been played enough.

| C# | E | G# | B | D# |
|---|---|---|---|---|
| 1 | ♭3 | 5 | ♭7 | 9 |
Pre-dominant or minor tonic — an m7’s job with more colour.
Also written C#min9, C#-9 or C# minor 9. The same chord either way; which spelling you meet depends on who wrote the chart.
Leave the root to the bass player. In a band nobody misses it, and the ear supplies it from the guide tones anyway.
The finger it frees goes to a tension, which is why these sound richer than the shape they came from rather than thinner.
C#m9 has 13 of them, on the top four strings, the middle four strings and strings 5-3-2-1, from open position up to the 12th — every inversion the chord has: E in the bass, G# in the bass, B in the bass and D# in the bass. The one to learn first is the D# shape at the nut, which is the easiest grip here.
5 of them sit on the top four strings, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with xx6857 — no barre and low, at the 5th fret. None of the shapes for C#m9 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 4 of the 7 need a barre. Together they cover the neck from the 2nd fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x4244x | 2nd fret | C#, root position | D# | barred |
| x66657 | 5th fret | D#, 9th in the bass | B | barred |
| xx6857 | 5th fret | G#, 2nd inversion | B | all fretted |
| 97x897 | 7th fret | C#, root position | B | all fretted |
| x79899 | 7th fret | E, 1st inversion | C# | barred |
| 9-11-9-9-9-11 | 9th fret | C#, root position | D# | barred |
| 12-14-13-13-14-12 | 12th fret | E, 1st inversion | E | all fretted |
The same notes rebuilt from scratch give 3 shell, 12 drop 2 and 8 drop 3 voicings, each on its own page.
Tensions. A shell of C#m9, root, third and seventh, leaves a string free, and the tones that belong over it are the 11 (F#) and the 13 (A#).
How you get to it. The turn that lands on C#m9 is D#m7♭5 to G#7♭9: the ii and the V of C# minor, which is where a minor tonic is usually arrived at rather than simply begun on.
In which keys. Every note of C#m9 belongs to C# minor (the i, the tonic), E major (the vi, the submediant), Ab minor (the iv, the subdominant) and B major (the ii, the supertonic).
Every note of C#m9 is in C# dorian and C# natural minor.
Change one note of C#m9 and you have C#m69 (the flat seventh becomes a sixth), C#m7 (drop the ninth), C#m11 (add the fourth), C#mMaj9 (the flat seventh becomes a major seventh), C#madd9 (drop the flat seventh) or C#9 (the minor third becomes a major third).
C#m9 is a minor chord — root, minor third, fifth. Minor chords on every root.
On C#m9’s sound and use this page follows Mark Levine, The Jazz Theory Book (Sher Music, 1995). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.