Single jug? That pitcher might do (9,4)
I believe the answer is:
jailhouse rock
'single' is the definition.
(Elvis Presley single)
'jug? that pitcher might do' is the wordplay.
'jug?' becomes 'jailhouse' (jug is a slang term for prison).
'that pitcher might do' becomes 'rock' (to pitch can mean to lean or rock).
'jailhouse'+'rock'='JAILHOUSE ROCK'
(Other definitions for jailhouse rock that I've seen before include "Elvis hit" , "Record" , "So jocular hike (anag) - hit song" , "Big hit" .)