Mark, Robert, Daymond and Kevin take their minds off business by singing Taylor Swift, but before you know it, they're competing again.

The superstar siblings relive childhood battles and compare horror movie screams in between sing-alongs to Violent Femmes and Steppenwolf.

When Gronk decides to try a career in music, Keegan trains with gruelling vocal warmups and a medley of timeless sports anthems.

The comedy icon and the hard-rocking sisters jam out to Madonna and Prince — and HAIM hits, of course — on a drive around Los Angeles.