Zumba students are not passive consumers of music. They focus intently on every bridge and chorus: Here's where I stomp my feet; here's where I shimmy to the left. They learn the songs, they love the songs, and they buy the songs. The music industry has noticed.

Fourteen million people take Zumba classes every week, and the many tens of thousands of Zumba instructors receive DVDs or CDs of new music monthly.

Zumba also distributes songs via mass-market CD compilations. In the most recent CD, a collaboration with Universal released in Europe, tracks from Nicki Minaj, the Black Eyed Peas, and Shakira alternate with original tracks from Zumba Fitness. Songs also enliven Zumba video games, of which the company's licensee has sold eight million copies.

For years, Zumba was the supplicant, begging record labels to let it use songs. Now both labels and individual artists are coming to Zumba.

Hip-hop star Pitbull was the first A-lister. In 2011, he created a special Zumba mix of "Pause," a track from his album Planet Pit, and Alberto ("Beto") Perez choreographed a routine for it.

The YouTube video of Perez doing "Pause" has been seen 5.1 million times.