Gb13 chord
The G-flat dominant thirteenth chord (abbreviated "Gb13 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 dominant eleventh chord.
In practice, the fifth (D♭) and eleventh (C♭) are often omitted from the Gb13 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.
Name
G-flat dominant thirteenth chord
Notes
G♭ B♭ D♭ F♭ A♭ C♭ E♭
Intervals
1 3 5 ♭7 9 11 13
Chord symbol
G♭13
Type
heptad (seven-note chord)