Senegal vocalist Youssou N'Dour became a teenage sensation with the band Etoile De Dakar, whose Xalis (1979) and Thiapathioly (1980) established mbalax (Cuban music performed with western instruments and augmented with African polyrhythms) as a major form of dance music. The formidable Immigres (1985) proved what kind of force of nature N'Dour's ensemble was, especially when coupled with the Middle-eastern inflection of his tenor, but Nelson Mandela (1986) began watering down the African element, shifting the emphasis from the percussion to the guitars, keyboards and horns, introducing stronger and stronger elements of funk, reggae and rock. The stylistic Babel of The Lion (1989), with Shakin' The Tree, was the natural result of this trend, that penalized the much more authentic and exciting Set (1990), perhaps his most emotional and most intricate ever, and eventually led to the fully westernized east-listening of Eyes Open (1992) and especially The Guide (1994), featuring the international hit Seven Seconds (1994), a duet with Neneh Cherry. Despite the slick production, Joko (1999) simply collects rearranged versions of tracks released only in Senegal. Rewmi (2000), Ba Tay (2001) and Nothing's In Vain (2002) are displays of style but have completely lost the tribal verve of mbalax.