Classical picks: Philadelphia Singers; Haydn's progressive piano music

Grand memorial. One of the more ambitious projects in the final seasons of the Philadelphia Singers under David Hayes was the 1958 Randall Thompson Requiem, a recording of which, made a year before the 2015 disbanding, is just out now on the Naxos label. This unaccompanied work for double choir has a freewheeling range of texts, traditional and otherwise, with music that certainly defies Thompson's image as a feet-on-the-ground Aaron Copland-era composer. At times, you wonder what Thompson was thinking by writing some of the more animated (and hard to tune) sections. But much vision is there - as well as great emotional generosity. Also surprising is how readily identifiable the full-throated Philadelphia Singers sound was. It's a grand memorial, for both composer and performers. - David Patrick Stearns