Any band that metamorphoses from a metal/hardcore hybrid to a more melodic outfit attracts "sellout" shouts from former fans. Scorned as it might be, this evolutionary process produces bivocal groups that have learned how to croon but still speak shriek fluently. Been-brutal bands sell their heavy segments more convincingly than started-out-screamo acts, much as a threat from a gone-straight gangster carries more weight than a pretty-boy temper tantrum. Underoath's first two albums, now fetching bankruptcy-baiting bids on auction sites, careened recklessly between black-metal riff and breakdowns. The Florida-based band excelled at eight-minute epics, endurance tests that exhausted its manic rhythm section and spastic singer. Today, behind new front man Spencer Chamberlain, the sextet aims for accessibility. With a few experimental exceptions (a choir chants "Drowning in my Sleep," a keyboard-and-click-percussion backdrop recalls the Postal Service), its latest release, They're Only Chasing Safety, follows a linear path from mildly chaotic verse to catchy chorus. But the occasional outbursts -- a serrated yowl overlapping an inviting hook, an erratic percussive pattern upsetting a steady pulse -- work because Underoath is experienced enough to play them with commanding authority.