Tiempo Libre: This Miami-based timba band is one of the most accomplished contemporary music ensembles in the country, no doubt in part because its members are graduates of an elite Cuban music conservatory. You can hear their early love of models such as the Earth, Wind and Fire horn section in their work, which covers everything from traditional Cuban songs like Guantanamera to takeoffs on the Well-Tempered Clavier of J.S. Bach. Their concerts are hugely energetic and muscular, a ferocious, tight band that leaves space for its members to improvise even as they call on everyone to dance. The band is giving two shows at Delray Beach’s Arts Garage; Saturday’s show is at 8 p.m. and Sunday’s at 7 p.m. Tickets start at $25; call 450-6357.