I'm gonna agree with the Violent Femmes for Roday...perhaps also Barenaked Ladies (earlier, geekier stuff) and They Might Be Giants. Hmmm...*thinks of camp music* There's also a slight probability of mid-70s to early-90s dance music. He'd also have classical, but I doubt he'd listen to it much--only when he really needed to concentrate.

Sheppard, no idea, but 80s sounds bout right too. :D