Just to help you get started...

Michael Green (humorist)

Also attributed to Michael Green is the theatre style of Coarse Acting. A coarse actor is "one who can remember his lines, but not the order in which they come. One who performs . . . amid lethal props. The Coarse Actor's aim is to upstage the rest of the cast. His hope is to be dead by Act Two so that he can spend the rest of his time in the bar. His problems? Everyone else connected with the production." (Michael Green)

Thus you can work out what a "Coarse Muso" would be.... :-)