Most sophisticated and intelligent musician

so·phis·ti·cat·ed/səˈfistiˌkātid/Adjective
1. (of a machine, system, or technique) Developed to a high degree of complexity.
2. (of a person or their thoughts, reactions, and understanding) Aware of and able to interpret complex issues; subtle.

bohemian (noun)

A person with artistic or literary interests who disregards conventional standards of behavior.

Hmmm. Thanks for the definition,CW. Seems to me he was both sophisticated in his understanding of complex feelings and issues, and bohemian in his lifestyle. Whether he was more of one attribute than the other can be debated. For me, his music is enough of an answer.

Gene Simmons - they call him Dr. Love.

Kid Rock - he's not straight outta' Compton, he's straight out the trailer.

Axl Rose - no explanation needed.

Peter Hammil
Joni Mitchell
Manos Hatzidakis