Well, it's actually "gozar" with a Z, and as others have translated it correctly, simply means to enjoy. Tito Puente, the author, was of Puerto Rican ancestry. In seven years of living in Puerto Rico and public school classes there I never heard the word used for anything more than simply to enjoy - in this case his rhythm, or have a good time listening to his music. I like the suggestion that mulata could refer, simbolically, to the mixed type of music. Makes sense.