Leave it to FX's perenially cranktastic It's Always Sunny In Philadelphia to push the telly-musical envelope, further shaping an entire episode around a “rock opera” with its cast of characters who usually can't be bothered to take a spare breath when they aren't shouting put-downs at one another. How would they stand still long enough to hit the high notes? As it turns out, the fourth-season finale, “The Nightman Cometh” (in which Charlie gets the gang to participate in a musical he shaped around the song he wrote back when Dee suspected her rapper boyfriend was handicapped … ah, good times), was a sweetly melodic opus infused with the kind of oh-so-wrong lyrical imagery you might expect from Philly's favorite no-goodniks. As actor Charlie Day put it in a behind-the-scenes feature on the episode, “It's sort of like a hybrid of Al Jolson and Bell Biv Devoe, with just a little bit of Aaron Copeland and a dash of Yanni.” If you missed it when it aired or simply can't get enough of the “Nightman” magic, the entire cast performs it in It's Always Sunny In Philadelphia LIVE at the Troubadour. If you managed to score tickets, get there early so you can sit close enough to see Danny DeVito in his troll outfit, and be ready to sing along with “It's Nature, Shit Happens.”

Fri., April 17, 8 p.m.; Sat., April 18, 8 p.m., 2009

LA Weekly