For anyone wishing musical theater wouldn't take itself so seriously, there's Diamond Lion. A simple set up—the cast performs a series of improvised scenes that eventually break into off-the-cuff songs—belies the athleticism required of it players. Just ask any of the guest stars. Each week, the pride invites a different performer to join, on one condition: that he or she has no musical-improv experience. It's a joy to watch this newbie be carried to lyrical greatness by the rest of the players.