C 11th chord
C11 chord for piano presented by keyboard diagrams.
Explanation: The C eleventh is a six-note chord. To avoid dissonance the third (E) is normally omitted. The chord is also often played inverted. The chord is abbreviated as C11.
Theory: The C eleventh chord is constructed by adding a third to a ninth chord.
Notes: C - E - G - Bb - D - F