Weather Report was an influential jazz fusion band of the 1970s and 1980s.
The band was originally a spin-off from the group of musicians associated with Miles Davis in the late sixties and early seventies. The stable core of the group was the duo of pianist Joe Zawinul and saxophonist Wayne Shorter, while the other musicians were rotated with almost every album. Initially, the band's music featured extended improvisation, similar to Davis' Bitches Brew-period work, and instrumentation included both a traditional trap set drummer and a second percussionist (first Airto Moreira, later Dom Um Romão). The group was unusual and innovative in abandoning the soloist-accompaniment demarcation of straight-ahead jazz and instead featuring continuous improvisation by every member of the band. Both Zawinul and original bassist Miroslav Vitouš experimented with rock guitarists' electronic effects, Zawinul on electric piano and organ, Vitous on upright bass, often bowed, as a second horn-like voice.
Starting with Sweetnighter, Weather Report's recordings became increasingly funk- and groove-oriented, while retaining the high improvisational content of the first few albums. Vitous's lack of interest in playing repetitive, funky vamps led to his replacement by Alphonso Johnson. For its first few years of existence the group had difficulty finding a permanent drummer, moving through Alphonse Mouzon, Eric Gravatt, Greg Errico, Leon 'Ndugu' Chancler, and Chester Thompson.
By 1976's Black Market, the group's music evolved from the open-ended funk jams of Sweetnighter and Mysterious Traveller into more melody-oriented, concise forms. They also achieved greater mass-market appeal. Most notably, this album introduced virtuoso bassist Jaco Pastorius into the group. It was with Pastorius that the group had its most popular success, resulting in their classic jazz standard "Birdland", from the Heavy Weather album in 1977. Pastorius departed the group in late 1981.
