FamousMaiden Voyage ChordMaiden Voyage, 1965 · Herbie Hancock
The first chord of the tune, vamped under the opening rhythm figure and the first bars of the A section
A D chord with the third replaced by a fourth (G) and a seventh and ninth added, which is the same as an A minor seventh over a D bass. With no third it neither resolves nor sounds major or minor, so it floats. Herbie Hancock built Maiden Voyage from four chords of this kind, moving them around instead of resolving them.
Also called Maiden Voyage voicing, D7sus4, D9sus4, Am7/D
Sources: Maiden Voyage (composition), Wikipedia · Suspended chord, Wikipedia · How to Play the 4 Maiden Voyage Chords (Contemporary School of Piano) · 9th sus4 chords on guitar (guitar-chord.org)