Cb11 chord
The C-flat dominant eleventh chord (abbreviated "Cb11 chord") is a six-note chord consisting of the notes C♭, E♭, G♭, B♭♭, D♭, and F♭. The chord is formed by adding an eleventh to a C-flat dominant ninth chord.
In practice, the third (E♭) and fifth (G♭) are often omitted from the Cb11 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.
Name
C-flat dominant eleventh chord
Notes
C♭ E♭ G♭ B♭♭ D♭ F♭
Intervals
1 3 5 ♭7 9 11
Chord symbol
C♭11
Type
Hexad (six-note chord)