Massively popular in his native Dominican Republic, Juan Luis Guerra has achieved crossover success worldwide with his sophisticated mix of tropical dance styles. After attending the prestigious Berklee School of Music, he returned home and formed vocal harmony group 440 that earned a reputation for sophisticated arrangements and precision tuning. He later added elements of the traditional ballad style known as "bachata," mixing it with rapid Merengue rhythms propelled by a two-headed drum called a "tambora." By incorporating African harmony and Caribbean melodies into a mix replete with saxophones, electric guitars, percussion and keyboards, he has produced a compelling hybrid of contemporary Latin music over his lengthy career. Revered for his lyricism, he has been known to drive people to tears and outrage politicians with his social commentary. By the 1990s, Guerra was cranking out global hits and expanding his musical range to include African guitar and Haitian rhythms, all the while maintaining his musical integrity.