Ab 7sus2 (Ab7sus2)
Also written as G# 7sus2 (G# and Ab are the same key).
Notes in Ab 7sus2
Inversions
Same notes as Ab 7sus2, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
G# in the bass
1st inversion
A# in the bass (Ab7sus2/A#)
2nd inversion
D# in the bass (Ab7sus2/D#)
3rd inversion
F# in the bass (Ab7sus2/F#)
Open voicings
A close-position chord like Ab 7sus2 can sound cluttered in the middle of the keyboard. Jazz players open it up by dropping one note down an octave, spreading the same notes wider without changing the chord.
Drop 2
D# on the bottom
Drop 3
A# on the bottom
Play G#, A#, D# and F# together and you get Ab 7sus2.
The sus2 cousin of 7sus4: the third is replaced by a major second, with a minor seventh underneath. It sounds more open and floating than a normal dominant seventh, and it resolves nicely down to the plain seventh when you want a little movement in a groove.