Are Dsus, Dsus2, and Dsus4 all the same chord? (R 4 5) Is Dsus2 more like (R, 4, 5, 9)? If so, why isn't it called Dsus4add9? Is "root, fourth, fifth" really the appropriate way to think about a suspended chord? I think Mark Levine has defined a suspended chord as "a chord voiced such that the major 4th does not sound like an avoid note" ; he doesn't explicitly say that the 3rd is omitted. Could I make a different inversion of the chord that contained both the 3rd and 4th and didn't sound dissonant? Can you make 7th chords suspended? D7sus? Dmaj7sus? Dmin7sus sounds especially strange to think about: it sounds like it would be equivalent to a D half-diminished chord.