Complex sentence: Some of these stars included Bob Hope, Jack Penny and the Marx Brothers, Judy Garland, Mae West, Milton Berle, Jimmy Durante, and Jerry Lewis who also performed on stage at RKO Keith's Theater.
Split into simpler sentences: Some of these stars included Bob Hope, Jack Penny and the Marx Brothers. Additionally, entertainers such as Judy Garland, Mae West, Milton Berle, Jimmy Durante, and Jerry Lewis who also performed on stage at RKO Keith's Theater.