Oh, to be young, beautiful and in the 1980s again… kind of like screen sensation Zac Efron on April 13, for example. The young star (born in 1987, for the record) of upcoming big screen release 17 Again blasted to the past at retro musical Rock of Ages, jamming out at the Brooks Atkinson Theatre to the tunes of Poison, Journey and many, many more like a seasoned concert-going pro. No mere groupie, Efron got a VIP pass to join the Rock of Ages cast backstage post-show, chatting with fellow singing stars Constantine Maroulis, Amy Spanger, Mitchell Jarvis and Lauren Molina, as well as power-rock player Tad Wilson, who went on as stoner club owner Dennis in place of Adam Dannheisser (who missed the night’s performance to welcome his second child into the world. Congrats to the Dannheissers!). So did the High Sc