Tango is a style of music in 2/4 or 4/4 time that originated among European immigrant populations of Argentina and Uruguay (collectively, the "Rioplatenses"). It is traditionally played on a solo guitar, guitar duo, or an ensemble, known as the orquesta típica, which includes at least two violins, flute, piano, double bass, and at least two bandoneóns. Sometimes guitars and a clarinet join the ensemble. Tango may be purely instrumental or may include a vocalist. Tango music and dance have become popular throughout the world.