The cast of Rock of Ages had a very special guest join the '80s party on November 15—pop superstar Ariana Grande! The Broadway vet, who made her debut on the Great White Way in 13 when she was 15 years old, headed back to Times Square to cheer on her half-brother Frankie J. Grande, who is currently playing Franz in the hit rock musical. Check out this adorable shot of Frankie, Ariana and the cast hanging out backstage, then see Rock of Ages at the Helen Hayes Theatre!