Gbm13 chord
The G-flat minor thirteenth chord (abbreviated "Gbm13 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 minor eleventh chord.
In practice, the fifth (D♭) and eleventh (C♭) are often omitted from the Gbm13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.
Name
G-flat minor thirteenth chord
Notes
G♭ B♭♭ D♭ F♭ A♭ C♭ E♭
Intervals
1 ♭3 5 ♭7 9 11 13
Chord symbol
G♭m13
Alternative symbols
G♭–13 G♭mi13 G♭min13
Type
Heptad (seven-note chord)