How much does the lack of a share button prevent you from "manually" sending the link to friends via Twitter/Facebook by copying and pasting? (I'm asking honestly -- and I'd like to prevent the site from getting gunked up with share links.)
So, I might not think of sharing it without seeing a button, and if I do think of sharing something, but requires me to copy, go to Facebook, write a note, paste, go to Twitter and do the same thing, I'll just be like "oh, forget it." (unless I'm really excited... I shared the general link on Facebook, but not any individual song).
I would think of sharing as a feature, rather than clutter. Here's my user story - "As a user, I want to share this tasty jam with my bandmate so we can shred together" (decided to have fun with that one).
It may be going to far, but you might even want to make sharing a song a call to action ("Did you enjoy this song? Share it with friends!" [followed by big fat Facebook & Twitter buttons])