Bb thirteenth chord
Bb13 chord for piano presented by keyboard diagrams.
Explanation: The B flat thirteenth is a seven note chord. Due to practical circumstances, some notes (as a suggestion fifth, ninth, and eleventh) is omitted and the chord is played inverted. The chord is often abbreviated as Bb13.
Theory: The Bb thirteenth chord is constructed by adding a third to an eleventh chord.
Notes: Bb - D - F - Ab - C - Eb - G