This 1961 recording is perhaps the most significant expression of what would come to be called the “Third Stream” movement, an attempt to fuse jazz and classical music conventions into something new and unique. While the movement itself never really took off, it did yield some intriguing and occasionally magnificent music; on this album there’s a thoughtful chamber-jazz composition by Jim Hall for guitar and string quartet, as well as modern classical explorations of musical themes by John Lewis and Thelonious Monk.