I'd be an internationally respected rock critic for Rolling Stone, traveling the highways and byways of America with bands in their tour buses and finding out what really makes them tick. Also, groupies.
Engineer. Perhaps beginning with creation of new materials, coupled with new methods of combining them and new methods of construction to create a mix of form and function that is both beautiful AND useful.
It might range from a new cooking pot to I 70 through Glenwood Canyon in Colorado.