C#dim7

C#dim7 is C#, E, G and Bb, a diminished seventh. The shape this page opens on is written xx2323, lowest string first.

Also written C#°7, C#o7 or C# diminished 7. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 6 common shapes for C#dim7 on the guitar, and 30 derived voicings in 4 families.

The common shapes, written lowest string first: xx2323, x45353, xx5656, 9x8989, 9-10-11-9-11-9, x-x-11-12-11-12.

Shell. Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top. C#dim7 has x4x353, 9x898x, x4898x, 9-7-8-12-x-x, 9-13-14-12-x-x.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. C#dim7 has x1202x, 3423xx, xx2323, x4535x, xx5656, 6756xx, x7868x, xx8989.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. C#dim7 has x1x020, 3x232x, x4x353, 6x565x, x7x686, 9x898x, x-10-x-9-11-9, 12-x-11-12-11-x.

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. C#dim7 has 005656.

Tensions. A shell of C#dim7, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (D#), the 11 (F#), the b13 (A) and the maj7 (B#).

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