One of the dangers of the annual Under Cover Weekend is the threat of having a band's temporary alter ego overtake its original persona. (After the Hibernauts' Four Tops set, I secretly want the quartet to only play Motown tunes dressed in matching dinner jackets.) If you missed this fall's all-covers celebration, you can catch two of the better sets at New Year's Eve at Off Broadway. Fattback will transform back into populist superpower Huey Lewis & the News, and the Monads will once again abandon banjos and fiddles in favor of electric guitars and synths and devolve into Devo. Both bands will perform two sets — one of originals and one of covers — and the all-male Madonna tribute band the Mandonnas will round out this free evening of '80s pop magic.