John Francis Anthony “Jaco” Pastorius III (/ˈdʒɑːkoʊ pæˈstɔːriəs/, December 1, 1951 – September 21, 1987) was an American jazz bassist who was a member of Weather Report from 1976 to 1981. He worked with Pat Metheny, Joni Mitchell, and recorded albums as a solo artist and band leader.His bass playing employed funk, lyrical solos, bass chords, and innovative harmonics. As of 2017, he is the only electric bassist of seven bassists inducted into the DownBeat Jazz Hall of Fame, and has been lauded as one of the best electric bassists of all time.

John Francis Pastorius was born December 1, 1951, in Norristown, Pennsylvania. He was the oldest of three boys born to Stephanie, his Finnishmother, and Jack Pastorius, a charismatic singer and jazz drummer who spent much of his time on the road. His family moved to Oakland Park in Fort Lauderdale when he was eight. Pastorius’ nickname, “Jaco”, became adopted, and was partially influenced by his love for sports as well as the umpire Jocko Conlan. In 1974, he began spelling it “Jaco” after it was misspelled by his neighbor, pianist Alex Darqui. His brother called him “Mowgli” after the wild boy in The Jungle Book because he was energetic and spent much of his time shirtless on the beach, climbing trees, running through the woods, and swimming in the ocean. He attended St. Clement’s Catholic School in Wilton Manors and was an altar boy at St. Clement’s Church. His confirmation name was Anthony, thus expanding his name to John Francis Anthony Pastorius. He was intensely competitive and excelled at baseball, basketball, and football.

He played drums until he injured his wrist playing football when he was thirteen. The damage was severe enough to warrant corrective surgery and inhibited his ability to play the drums.

Before recording his debut album, Pastorius attended a concert in Miami by the jazz fusion band Weather Report. After the concert, he approached keyboardist Joe Zawinul, who led the band. As was his habit, he introduced himself by saying, “I’m John Francis Pastorius III. I’m the greatest bass player in the world.”Zawinul admired his brashness and asked for a demo tape. After listening to the tape, Zawinul realized that Pastorius had considerable skill. They corresponded, and Pastorius sent Zawinul a rough mix of his solo album.

After bassist Alphonso Johnson left Weather Report, Zawinul asked Pastorius to join the band. Pastorius made his band debut on the album Black Market(Columbia, 1976), in which he shared the bass chair with Johnson. Pastorius was fully established as sole band bass player for the recording of Heavy Weather(Columbia, 1977), which contained the Grammy-nominated hit “Birdland“.

During his time with Weather Report, Pastorius began abusing alcohol and illegal drugs, which exacerbated existing mental problems and led to erratic behavior.^[13] He left Weather Report in 1982 due to clashes with tour commitments for his other projects, plus a growing dissatisfaction with Zawinul’s synthesized and orchestrated approach to the band’s music.

Warner Bros. signed Pastorius to a favorable contract in the late 1970s based on his groundbreaking skill and his star quality, which they hoped would lead to large sales. He used this contract to set up his Word of Mouth big band which consisted of Chuck Findley on trumpet, Howard Johnson on tuba, Wayne Shorter, Michael Brecker, and Tom Scott on reeds, Toots Thielemans on harmonica, Peter Erskine and Jack DeJohnette on drums, and Don Alias on percussion. This was the group that recorded his second solo album, Word of Mouth (Warner Bros., 1981).