Gosh, that's a hard one because I have so many choices springing to mind. Where do I begin?

There are six musicians I can think of immediately whom I would love to have playing for me:

Marvin Gaye (what a crooner! So sexy too. His rendition of Star Spangled  Banner gave me goosebumps.)

Bob Marley  (The reggae maestro. I could listen to him all day!)

Elvis Presley ( I loved many of his songs because he was so original)

Sam Cooke (Wow, wow! What a voice - not to mention the looks!)

Otis Redding (Another guy with a fab voice and looks)

All of them chosen for different reasons. See my final choice in my comment. 

Over to you. :o)