Possible Clues:

• One of those who can do something when he gets his hands on the keys for one of those rappers behind bars
• Orchestra member
• One blowing their own trumpet?
• Mercury or Mars, e.g
• Violinist, e.g.
• Player's foul in a miscue, almost
• American chemical company taken in by staff person on the fiddle perhaps
• Professional instrumentalist
• As a player I am in such short supply
• His sounds a possible career?