Pirate singing bawdy sea shanty (7)
I believe the answer is:
corsair
'pirate' is the definition.
(corsair is a kind of pirate)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for corsair that I've seen before include "Pirate from N. Africa" , "A swift pirate ship" , "Marauder" , "Seafarer" , "Buccaneer" .)