RCA Red Seal Records (now a division of Sony Masterworks) has just released the complete Chicago Symphony Orchestra recordings—some available for the first time on CD—led by Morton Gould, a frequent and favorite guest conductor in the 1960s.

“This set of recordings documents an unusual relationship Gould had with the Chicago Symphony Orchestra,” writes Alan G. Artner in the set’s liner notes. “[This] collection represents something close to the height of Gould’s work in the recording studio, made with the finest orchestra he conducted, taking chances with a good deal of music just being discovered in that adventurous, bygone time.”

Read more: Morton Gould + CSO = 6