At their Boston show last week, the outfit worn by Psychedelic Furs front man Richard Butler--a chunky beaded necklace, dapper suit and secret-agent sunglasses--embodied his band's descent into glossy rock purgatory. Formed in 1977, the Furs' early albums were shadowy hurricanes of post-punk rebellion. Butler's tar-smeared vocals matched the group's squawking saxophones, sandpaper-raw riffs and unflagging energy. Yet his bombastic grittiness found itself at odds with the Furs' sound and vision during their mid-1980s heyday, when a re-recorded version of "Pretty in Pink," dark anthems gussied up with synths and a hairsprayed mallrat makeover, catapulted them to stardom here. His voice remained nicotine-raspy in Boston, but the show's atmosphere strictly felt like a nostalgia trip back to senior prom 1982. The lukewarm, keyboard-driven "Alice's House" dragged, and even once-crisp jags like "Into You Like a Train" felt bogged down by arena-cheesy drumming. Hits "Love My Way," "Heartbreak Beat" and "Pink" naturally made joyful appearances, but their upbeat attitude felt no different from the performance of moodier cuts like "President Gas"--an unfortunate but not surprising avoidance of the soul-searing sentiments that once made them innovators.