When this site housed the Rendezvous Room at the Senator Hotel, many entertainment greats, including Louie Armstrong, Billie Holiday, Ella Fitzgerald and Dinah Washington performed here. See, for ex., https://phillyjazz.us/2015/12/21/rendez-vous-club/ and http://www.ocfrealty.com/naked-philly/washington-square-west/delorean-time-machine-irving-house (comments say building here now chills water for hospital). I first heard of it in Milestones (Phila. Corp. for Aging), July 2017, p. 15, column by Don Harrison. Mr. Harrison wrote that Ronny Graham, program consultant on the M*A*S*H television show, had been a stand-up comedian here.