Wiktionary
hit it
phr. (context informal English) Start performing; start playing a song, etc.
Usage examples of "hit it".
Parker went over to the door to the fruit cellar and hit it with his fist.
He was about my grandfather's age, but we hit it off, and we were jabbering away when my mother walked in.
He leapt - very suddenly - back into the landing craft and screamed: 'Hit it!
In the second day's fighting, Union cavalry general James Wilson's men got behind the Army of Tennessee and attacked it from the rear while Thomas' infantry hit it from the front.