Found via the Springsteen sub-reddit, here is an advertisement for an April 1973 concert, where Bruce Springsteen opened for Chuck Berry and Jerry Lee Lewis. According to Brucebase, Springsteen and company were told about a week before that they had to be Chuck Berry's backing band. So, with very little practice, the boys went out there and improvised with Berry for 70 minutes. Unfortunately, there exists no recording of this show. But, I think we can safely assume that the concert goers got their $5.50 worth that night (roughly $30 today).