That job got them their own record deal, and with a bevy of studio musicians backing them (including future Doobie Brother Jeff "Skunk" Baxter) they created Steely Dan. His website said he died on Sunday.
After working as touring musicians they moved to Los Angeles, releasing the first Steely Dan album in 1972, "Can't Buy a Thrill". Becker, who co-founded the band, was Steely Dan's guitarist and bassist.
Becker told Rolling Stone in 1974.
Becker was careful to distance his music from the "fusion" wave that was taking shape in jazz at the time.
Steely Dan performs during the Coachella Valley Music and Arts Festival in Indio, CA Friday, April 10, 2015.
He met Fagen at Bard College in NY in 1967 and the pair "would bond over their love of this music", Reuters reported.
This Nov. 20, 2008 file photo shows musicians Walter Becker, left and Donald Fagen of the band Steely Dan perform at "Collaborating for a Cure" the Samuel Waxman Cancer Research Foundation Benefit Concert in NY.
According to Reuters, Becker was born in New York City in 1950, where he "grew up revering the jazz giants Charlie Parker, Duke Ellington and John Coltrane". "Given the nature of these times, this may be precisely the quality that makes Walter Becker and Donald Fagen the ideal musical antiheroes for the Seventies".
Becker's official site announced the guitarist's death; no cause of death or other details were provided. At the dawn of the '70s, such prefabricated tunes were falling out of fashion, swept aside by the idiosyncratic, individualistic pop that surfaced in the wake of rock & roll.
"It wouldn't bother me at all", Becker said in an interview, "not to play on my own album".