In 1970, Zawinul cofounded
Weather Report with saxophonist and Davis alumnus
Wayne Shorter. Their first two years emphasized a relatively open, group improvisation format not dissimilar to what Miles Davis was doing in a more rock oriented format. However, Josef started making changes with their 3rd album, "Sweetnighter", citing he was "tired of waiting for something to happen". Funk elements such as electric bass, wah-wah pedal, etc. started to be introduced in the band's sound. Music critics generally agree that their 4th album,
Mysterious Traveller, was their true breakthrough album, capturing the classic Weather Report "sound" for the first time. The musical forms were now through composed similar to classical music, and the combination of jazz harmonies with 70's groove elements launched the band into its most successful period.
Their biggest commercial success came from his composition "
Birdland", a 6-minute opus featured on Weather Report's
1977 album
Heavy Weather, which peaked at number 30 on the
Billboard pop albums chart. "Birdland" is one of the most recognizable jazz pieces of the 1970s, covered by many prominent artists from
The Manhattan Transfer to
Maynard Ferguson and
Jefferson Starship. Even Weather Report's version received significant mainstream radio airplay — unusual for them — and served to convert many new fans to music which they may never have heard otherwise.
Weather Report was active through the '80s, with Zawinul and Shorter remaining the sole constant members through multiple personnel shifts. Weather Report was also notable for bringing to prominence pioneering fretless bass guitarist
Jaco Pastorius.