Ray Manzarek, who as the keyboardist and a songwriter for the Doors helped shape one of the indelible bands of the psychedelic era, died on Monday at a clinic in Rosenheim, Germany. He was 74.

The cause was bile duct cancer, according to his manager, Tom Vitorino. Mr. Manzarek lived in Napa, Calif.

Mr. Manzarek founded the Doors in 1965 with the singer and lyricist Jim Morrison, whom he would describe decades later as “the personification of the Dionysian impulse each of us has inside.” They would go on to recruit the drummer John Densmore and the guitarist Robby Krieger.

Mr. Manzarek played a crucial role in creating music that was hugely popular and widely imitated, selling tens of millions of albums. It was a lean, transparent sound that could be swinging, haunted, meditative, suspenseful or circuslike. The Doors’ songs were generally credited to the entire group. Long after the death of Mr. Morrison in 1971, the music of the Doors remained synonymous with the darker, more primal impulses unleashed by psychedelia. In his 1998 autobiography, “Light My Fire,” Mr. Manzarek wrote: “We knew what the people wanted: the same thing the Doors wanted. Freedom.”