"Some Nights" fun.

Now comes the hard part. After an unexpected and impressive six-week run at #1 earlier this year with the anthemic "We Are Young," fun. hopes to avoid becoming the latest breakthrough alternative act to burn bright and flame out quickly on the charts. (Think Foster the People, Owl City, Feist...) Follow-up single "Some Nights" certainly makes a statement with its striking a cappella opening: an enormous sonic wall of harmonizing voices. But the song's searching lyrics and grand scope—a series of moving parts, including pounding drums, soft keyboard and Auto-Tuned vocals, so dynamic that it feels like a pop symphony—are not exactly omens of crossover success. While we wait for a resolution to this question of one-hit wonder status, the New York City-based band nevertheless deserves prop for its ambition. B+