American R&B has long had a Europhile streak, boosting beats from clubs in London, Stockholm and elsewhere. Now the U.S. charts are making room for actual Europeans: U.K. singer-producer Taio Cruz’s single “Break Your Heart” crashed in at Number One. Cruz’s formula is throbbing sentiment plus throbbing rhythms — plaintive melodies delivered over synth-strafed beats. It works when the hooks are big and boisterous enough (e.g., the sleazy Ke$ha collabo “Dirty Picture”). But Cruz’s singing lacks personality, and Rokstarr is ultimately a collection of decent, but generic, Eurodisco tracks without a star — “rok” or otherwise — to hold a listener’s interest.