Q: i don't understand the harmonic function of Sus chords. Seems to me like a chord that's dominant but cute, and like a shortcut to chords that leads to another colours. what do you think about it?
A: a good starting point to understanding sus chords is: play a C major triad (C, E, G). ok now play it with F note instead of E: (C, F, G). that is called Csus4. ok now play Csus4, then C. nice! Ok now also there is a rumor going around that if you use 2 instead of 4 (C,D,G) that is called Csus2, but that one doesn't really take as much pleaseure in the resolve as the Csus4 to C resolve. but it's still easier to say Csus2 than to say Cadd2no3. even quicker to just say C2, which is what i usually say. also you may have noticed that Csus4 can be the same as Fsus2, depending on whether the bass player is playing C or F. i'm not sure if that answers your question.