Work on a fourth LP was in the works and during 1974, Chase had been performing a melodic flugelhorn piece called "Ode To A New England Jellyfish" written by Bill; this tune was recorded during the summer of 1974 and was only missing Bill's solo section.

A number of other charts were slated for potential inclusion, including "2001" a space odyssey theme (arranged by Bob Odjeda), an instrumental version of "Aphrodite" (from the Ennea LP) retitled "Shades of Venus," and Bill's arrangement of "MacArthur Park."

[1] In his retrospective review for AllMusic, critic Ross Boissoneau wrote that the album "represented a dramatic change in direction for the band.

Where the group's first two albums were standard if scintillating jazz-rock not all that different from Blood, Sweat & Tears or Chicago, Pure Music pointed the way to fusion.

"[2] In addition to a conventional stereo version, the album was released by Epic in a quadraphonic edition on LP and 8-track tape in 1974.