07/30/2008 at 06:10 AM EDT
made his deejay debut Tuesday night at Green Door lounge
in Hollywood, with a surprising guest in the crowd – his ex-girlfriend Rachel McAdams
Arriving at 9 p.m., the actor settled into what is said to be a weekly gig at the lounge's Tuesday jazz night. McAdams arrived later "supporting Ryan," says a Gosling pal.
"They talked when he was away from the deejay stand," says the friend. "They really looked like good pals. He seemed happy to see her."
For Gosling, deejaying is "a pretty new thing for him," says the friend. "He's been messing around. He's really into music, and he's a fan of the night – and here he is."
Spinning tunes from the '40s and '50s, Gosling, 27, was dressed from the era, sporting a white T, black pants and motorcycle jacket.
Along with McAdams other celebs on hand were Catherine Keener, Shane West and hockey ace Sean Avery, who chatted up an enamored Keener.
Once the live jazz band took the stage, Gosling mingled with friends and hung out on the patio.