This afternoon of spectral ambient explorations at PS1 pairs up two master soundscapists. As Grouper, Liz Harris deconstructs guitar-and-voice folk singer-songwriter-craft into haunting, ethereal dronescapes. She performs entirely new music here set to projected visuals by filmmaker Paul Clipson. Joining her is avant-composer William Basinski who specializes in ghostly ambient works created using tape loops and radio static alongside conventional instruments. Renowned among experimental-music geeks for his Disintegration Loops series, he turns up to present his latest work, Cascade.