Aimee Mann and Elvis Costello off pure lyrics writing merits, for instance. Talking Heads are also pretty damned bright musically, even if a fair deal of it comes from muscle memory. R.E.M., especially in their pre-Life's Rich Pageant period. I'm also kinda shocked you don't acknowledge Blondie, at least pre-Parallel Lines, although they fit squarely into sounding dumb as well. It's not quite mathematical and precise like a few guitar heroes, but You underestimate how much I'm capable of appreciate a cerebral - or at least minimally thoughtful - approach to music.