Varying ways in which artists approach their music

When I think of intellectual I think of progression, not putting out the same album over and over with slight variation. With that in mind:
Joe Jackson.
Jane Siberry
Ryan Adams
Those three immediately popped into my head. I'll come up with some newer artists in a bit.

I'm impressed by Jack White. From the White Stripes to his project with Loretta Lynn to his new blues album and everything in between is a broad range of styles and he really seems to immerse himself in each genre he tries. He doesn't come across as a shallow poser to me but more like a kid in a candy store exploring all the different ways to express himself musically. I'm heading out to pick up his new album today. I agree with the Ryan Adams recommendation, too. I think these two guys are deeply intellectual in their approach to music and are going to be around for a long time and produce huge and varied bodies of work similar to what Randy Newman has given us.

First thoughts:

David Byrne
Brian Eno
Peter Gabriel
Beck
Moby
Brian Wilson (crazy, but intellectual)
Peter Green (as above)

All folks who tried to take their act to an interesting new place.

Appreciate the responses. Ryan Adams is one of my favorites also.