On paper, there’s nothing likable about Vampire Weekend, a band made up of Columbia University students who describe their sound as “Upper West Side Soweto,” a reference to their blend of preppy indie rock and Afrobeat. But somewhere in their xylophone and harpsichord racket and seeming worship of Paul Simon’s Graceland, there is an odd earnestness that works. Rhythms are what drive this band, and they vary from Brazilian funk to wild dancehall. “Holiday” races around offbeat ska that breaks into keyboard flurry, while opener “Horchata,” an ode to the Mexican beverage, is built around tribal drumming and African chanting. All the while, singer Ezra Koenig weaves his boyish voice through the rhythm. Make it your next guilty pleasure.