You've heard of salsa. But you may not have heard of its upstart offspring, timba.

Pronounced TEEM-ba, the musical form is at the heart of the sound of Miami's Tiempo Libre, the seven-man band performing Friday night at the Bloomington Center for the Performing Arts.

At its simplest, the band's music director Jorge Gomez describes it as a hard-driving fusion of jazz and the Havana tradition of salsa exemplified by groups like the famed Buena Vista Social Club (introduced to many Americans via Wim Wenders' popular 1999 film documentary of the same name).

The strain of Cuban salsa Gomez refers to is also known as "son montuno," the form that stretches back to the late 19th century.

As it has evolved over the decades, timba has come to encompass such influences as funk, rap, hip-hop, disco, Latin jazz.

Among the pioneering bands in the form are such groups as Los Van Van, Irakere and NG La Band, whose 1989 album, "En La Calle," is generally regarded as the first true timba album.

In the '90s, as the new sound continued to evolve, another Cuban band, La Charanga Habanera pushed the envelope further, paving the way for the Miami-based explosion of the past 10 years.

In addition to Tiempo Libre, other Miami-based timba bands include Tomasito Cruz and his Cuban Timba All Stars, El Tumbao and El Medico de la Salsa.

Gomez says the element that distinguishes timba from its salsa forebear is its higher levels of rhythmic energy and momentum, something he says is externalized through the band's highly physical stage show, which even employs a professional choreographer.