Weather Report's self-titled electronic and psychedelic "Weather Report" debut album caused a sensation in the jazz world on its arrival in 1971, thanks to the pedigree of the group's members (including percussionist Airto Moreira), and their unorthodox approach to music. The album featured a softer sound than would be the case in later years (predominantly using acoustic bass with Shorter exclusively playing soprano saxophone, and with no synthesizers involved), but is still considered a classic of early fusion. It built on the avant-garde experiments which Joe Zawinul and Shorter had pioneered with Miles Davis on "Bitches Brew", including an avoidance of head-and-chorus composition in favour of continuous rhythm and movement – but took the music further. To emphasise the group's rejection of standard methodology, the album opened with the inscrutable avant-garde atmospheric piece "Milky Way", which featured by Shorter's extremely muted saxophone inducing vibrations in Zawinul's piano strings while the latter pedalled the instrument. "Down Beat" described the album as "music beyond category", and awarded it Album of the Year in the magazine's polls that year.