This Atlantic release has some unusual performances by the Modern Jazz Quartet.
Two selections ("Da Capo" and "Fine") combine the MJQ, which is comprised of vibraphonist Milt Jackson, pianist John Lewis, bassist Percy Heath, and drummer Connie Kay, with the Jimmy Giuffre 3 (Giuffre on clarinet and tenor, with guitarist Jim Hall and bassist Ralph Pena) on "Exposure"; six chamber classical musicians add color, and a pair of other numbers ("Conversation" and the very successful "Sketch") match the MJQ with the Beaux Arts String Quartet.
There is plenty of thought-provoking music on this disc even if the idea of creating a third stream between jazz and classical music never came to pass.