Bb eleventh chords
Bb11 chord for piano presented by keyboard diagrams.
Explanation: The B flat eleventh is a six note chord. Due to practical circumstances and/or dissonance the third (D) is omitted and/or the chord is played inverted. The chord is often abbreviated as Bb11.
Theory: The Bb eleventh chord is constructed by adding a third to a ninth chord.
Notes: Bb - D - F - Ab - C - Eb