This album, recorded live onstage at the 2011 Vancouver Jazz Festival, is a remarkable one-off in the catalogs of both Mats Gustafsson (who plays tenor and baritone sax) and Colin Stetson (who plays alto and bass sax). Their four duo encounters, ranging in length from five to twelve minutes, include long drones, clacking valves, sudden explosive roars, direct challenges extended to each man by the other (and met in kind)…at times, it sounds more like Sunn O))) than avant-garde jazz, but there are also passages of quiet, subtle interaction. Play it loud and it’ll move small objects off your shelves, but on headphones it’s an almost psychedelic experience.