C11

C11 is C, G, Bb, D and F, a dominant eleventh. The shape this page opens on is written x32311, lowest string first.

Note by note. C is the root, G is the fifth, Bb is the flat seventh, D is the ninth and F is the eleventh.

Also written C9sus4 or C dominant 11. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 6 common shapes for C11 on the guitar, and 60 derived voicings in 4 families.

One note away. Change a single note of C11 and you have Csus2sus4 (with one note taken away), Cm9 (with one note moved), Cm11 (with one note added), C7sus4 (with one note taken away) or C9 (with one note moved).

In which keys. Every note of C11 belongs to C minor (the i), D minor (the ♭VII), Eb major (the vi), F major (the V), G minor (the iv) and Bb major (the ii).

The common shapes, written lowest string first: x32311, x33353, x75566, 870066, 888988, 10-10-10-10-11-12.

Under the hand. None of the shapes for C11 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 3 of the 6 need a barre. Together they cover the neck from the 1st fret to the 12th.

Where it goes. C11 is the V of F, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into F.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. C11 has 1303xx, xx0311, xx3313, x1301x, x3333x, 3333xx, xx5566, xx8768.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. C11 has x3x331, 1x031x, x1x011, 3x331x, 6x353x, x3x363, x5x566, x8x586.

Rootless. The root left to the bass player. Frees a finger for a tension. C11 has x1303x, xx3333, xx5766, x8878x, x-x-8-10-8-10, x-10-12-10-11-x, x-x-12-12-11-13, x-x-15-15-15-15.

Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. C11 has xx0066, 6x006x.

What kind of chord this is. C11 is a dominant chord — root, major third, fifth, minor seventh. dominant seventh chords on every root, and what they are for.

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.