Rock City was a nightclub in Gotham City.
History
Cassidy attends Rock City for its opening where singer "Soul Man Supreme" Sam Pryor and action movie star Trent Wallace were also present. The DJ of the nightclub was Howlin' Jake.
During Cassidy's appearance, the club was attacked and set ablaze by Firefly. Batman and Batgirl arrived at the scene and rescued Cassidy, along with Pryor and Wallace.