The G-flat major thirteenth chord (abbreviated "Gbmaj13 chord") is a seven-note chord consisting of the notes G, B, D, F, A, C, and E. The chord is formed by adding a thirteenth to a G-flat major eleventh chord.

In practice, the fifth (D) and eleventh (C) are often omitted from the Gbmaj13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.

Name
G-flat major thirteenth chord
Notes
G B D F A C E
Intervals
1 3 5 7 9 11 13
Chord symbol
Gmaj13
Alternative symbols
G13 Gma13 GMA13 GM13
Type
heptad (seven-note chord)

Gbmaj13 chord on piano

Gbmaj13 chord on guitar

Gbmaj13 chord on ukulele

Gbmaj13 chord on the staff