B major 13th chord
Bmaj13 chord for piano with keyboard diagram.
Explanation: The B major thirteenth is a six-note chord (the 11th, E in the case of Bmaj13, is normally excluded). For practical reasons the chord is normally played with omitted notes and/or inverted. It is often abbreviated as Bmaj13 (not to be confused with B13).
Theory: The B major thirteenth chord is constructed by extending the major eleventh chord with a major thirteenth note.
Notes: B - D# - F# - A# - C# - G#