The US saxophonist Chris Potter has been one of the world’s most creative interpreters of other people’s jazz since the early 90s, but though he has made plenty of albums as a leader, a more recent move toward more concept-led ventures is broadening his palette. The title music here is a four-part suite written for a combination of Potter’s regular Underground band, two basses and a string quartet. Though the leader doesn’t wholly integrate the different styles here, several passages do successfully sidestep the classical-meets-jazz feeling he hopes to avoid. The opening Lament (a tenderly melancholy strings theme with rich bass undercurrents, a soft backbeat and some beautiful tenor-ballad playing) and the pulsating finale, Shadow Self (influenced by Béla Bartók’s string quartets and featuring Potter on bass clarinet), are beautifully balanced pieces; though the main suite is a more uneven fusion, this feels like a work in progress with a fascinating future.