Brooklyn duo Sleigh Bells caused a joyful ruckus in 2010 with Treats, a startling debut that crashed Derek Miller’s monster riffs into Alexis Krauss’s girly cooing. Having lost the shock of the new, this more tuneful follow-up privileges Krauss’s pop instincts over Miller’s mayhem. They’ve managed the difficult trick of evolving a gonzoid sound, as the sultry, Pixies-ish ”Road To Hell” attests. “Never Say Die”, meanwhile, opts for insistent baroque pop. Having managed their anger, Reign of Terror feels misnamed. “Demons” and “True Shred Guitar” – the least adulterated tracks – are the standouts here, recalling the lurid fun of their debut. Sophomore slump? not quite, but certainly not the follow up we were hoping for.