Ab Suspended 2nd (Absus2)
Also written as G# Suspended 2nd (G# and Ab are the same key).
1+2+5
Notes in Ab Suspended 2nd
G# (root)A#D#
Inversions
Same notes as Ab Suspended 2nd, 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 (Absus2/A#)
2nd inversion
D# in the bass (Absus2/D#)
Ab Suspended 2nd is built from G#, A# and D#.
Suspended chords pull the third out entirely, so they land somewhere between major and minor rather than picking a side. Sus2 fills the gap with a major second sitting close to the root, which gives it an open, slightly hollow color. It's a favorite way to add movement to a strummed or arpeggiated part without changing the underlying harmony.