Basement Jaxx's house music brims with unbridled joy; their secret is the spirit of unfettered fusion that gives multicultural London its spark. On “Tonight,” flamenco guitars brush against Bollywood strings, and the clubby “Bongoloid” is UK garage with a giddy Balkan touch. They're at their zaniest on the mutant R&B of “Twerk,” complete with Auto-Tuned vocals that quote the theme from Flashdance.