 The son of a classical violinist and a ballet instructor, Slon was raised in São Paulo and began recording professionally at an early age, taking first place in a national poll of jazz critics while still a teenager.He performed alongside his father in the São Paulo Philharmonic, before appearing with the Walter Wanderley Trio, as well as Sérgio Mendes' Brasil '66 and Brasil ‘77 during the 1960s and 1970s.He also appeared on many Brazilian sessions overseen by Creed Taylor for the Verve label, including "A Certain Smile, A Certain Sadness" by Astrud Gilberto and The Walter Wanderley Trio, "Wave" by Antônio Carlos Jobim, and "Samba '68" by Marcos Valle.