semicord

Gb7#9 Gb dominant seventh sharp nine chord

Notes
Gb Bb Db Fb A
Formula
1 3 5 b7 #9
Semitones
0 4 7 10 15 above the root
Also written
F#7#9 (F# A# C# E G##)
Other symbols
Gb7(#9), Gb7+9

Gb to Bb is a major third (4 semitones), Bb to Db is a minor third (3 semitones), Db to Fb is a minor third (3 semitones), Fb to A is a perfect fourth (5 semitones). A dominant seventh with a raised ninth, A. On the keyboard A is the same key as the minor third, so the chord holds both a major and a minor third; it is written as a sharp ninth because it sits above the seventh and the letter names follow the stack of thirds.

Gb7#9 on the piano

C4D4E4F4G4A4B4C5D5Fb5F5G5A5B5C#4Eb4Gb4Ab4Bb4Db5Eb5F#5Ab5Bb5C4GbBbC5DbFbA

Root position from Gb4: Gb4, Bb4, Db5, Fb5, A5. Middle C is C4.

Gb7#9 on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has Gb as its lowest note.

8fr×GbGbBbBbFbFbAA×
A-shape, root on the A string at fret 9
x 9 8 9 10 x (low E to high e)
Sounds Gb3 Bb3 Fb4 A4, fifth left out

The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant seventh sharp nine chords on other roots.

Inversions of Gb7#9

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionGb Bb Db Fb AGb7#9
1st inversionBb Db Fb A GbF#m7/A# (also written Gbm7/Bb; also read as Gb7#9/Bb)
2nd inversionDb Fb A Gb BbGb7#9/Db
3rd inversionFb A Gb Bb DbGb7#9/E
4th inversionA Gb Bb Db FbF#7/A (also written Gb7/A; also read as Gb7#9/A)

Where Gb7#9 fits

Gb7#9 has no place among the chords built from a major or minor scale: it holds a major third, Bb, and the sharp ninth A, which sounds the same as the minor third. That major–minor clash is the blues in one chord. It is used as the I chord of a blues or a funk vamp, and as a tense V chord in jazz; Jimi Hendrix's "Purple Haze" made E7#9 famous, which is why guitarists call it the Hendrix chord.