Walter Becker, the multi-talented musician who co-founded Steely Dan, has died of an unspecified ailment at age 67. With the group's co-leader Donald Fagen, Becker created some of the most popular and acclaimed albums of the 1970s, with a jazz-inflected sound that built smoothly accessible tracks out of sophisticated underlying structures.

Becker's death was confirmed on his website, but no further details regarding the specifics of his ailment have been announced. Becker was forced to miss recent Steely Dan concerts due to illness; at the time, Fagen expressed the hope that his longtime collaborator would be able to recover.

Fagen and Becker founded Steely Dan in the early 1970s after playing together in Jay and the Americans and collaborating as songwriters. Like numerous other rock groups of the era, Steely Dan focused on creating cohesive, complex, sonically pristine albums — in fact, they retired from touring in 1974 to focus on their studio craft.

What distinguished Steely Dan was a smooth sound, reflecting a strong jazz influence, that helped them achieve popular success with hits including the top-ten smashes "Do It Again" (1972), "Rikki Don't Lose That Number" (1974), and "Hey Nineteen" (1980). They also eschewed the Me Decade's excesses for a more disciplined, quietly witty, affect that made them, as characterized by Rolling Stone, "the perfect musical antiheroes for the Seventies."

The core duo were the only constant members of a group that eventually became known for its legions of "supergroup" collaborators on albums like Aja (1977). In addition to the popular success that made Steely Dan radio staples, the group have earned continuing critical raves for albums that are now regarded as classics. In a poll last year, The Current's listeners ranked Aja at #172 and the group's debut Can't Buy a Thrill #711 on a list of the 893 Essential Albums of the rock era.

After a 12-year hiatus, Steely Dan reunited in 1993; 2000's Two Against Nature, their first LP in 20 years, earned a Grammy for Album of the Year. They were inducted into the Rock and Roll Hall of Fame in 2001. In a typically subversive move, the group chose not to make an acceptance speech; instead, Becker opened the floor to questions from the audience. MTV perfectly captured the group's legendarily laconic spirit in its headline: "Aerosmith thrilled, Steely Dan unimpressed at Rock Hall ceremony."