"Vento Sul" (1972) found Valle long-haired and bearded, and backed by the progressive rock band O Terço. His most experimental effort to date (he even flirted with heavy metal on the song "Mi Hermoza"), it was a sales flop, although it has acquired admirers over the ensuing decades. The following year's innovative "Previsão do Tempo" fared better. It was made in conjunction with the band that initially formed to back Valle at live shows and named itself after one of his songs, Azimuth (soon to change the spelling to Azymuth). This album had a notable jazz fusion feel thanks to Valle's enthusiasm for the Fender Rhodes piano and Azymuth keyboardist Jose Roberto Bertrami's expertise on the Hammond organ and assorted synthesizers such as the Mini-Moog and the ARP Soloist. This sound would prove a decisive influence on the acid jazz scene in Europe twenty years later. Another innovation in "Previsão do Tempo" was the use of vocal percussion on the track "Mentira", ten years before hip-hop artists introduced beatboxing. Valle emulates a drum kit with his voice to perform a pattern and a fill.