In 1986, Sérgio and Odair began to perform officially with the innovative Millennium guitar model, created by North American luthier Thomas Humphrey. The instrument had a different angle on the front top, allowing greater reach for the left hand and facilitating the execution of more complex passages, further expanding the musical possibilities.
It was playing on these guitars that they recorded their first album for Nonesuch, “Sergio & Odair Assad – Latin American Music for Two Guitars”. In this album, in addition to works that proved to be definitive in his career, "Tango Suite", by Piazzolla, and "Suíte Retratos", by Gnattalli, Sérgio also launched himself as a composer, with "Recife dos Corais", "Valseana", "Vitória Régia" and "Pinote".
Subsequent releases continued to include pieces by Sérgio, as well as works by renowned Latin American composers — such as Hermeto Pascoal, Egberto Gismonti and Alberto Ginastera, among others — and also by his daughter, Clarice Assad, born in 1978, who would become one of the most important composers and performers of her generation.
Duo Assad's sequence of albums extended to both Nonesuch and GHA — the Belgian record company responsible for releasing the duo's first international album, "The Debut Concert: Live in Brussels" (1983).