The Icelandic artist Ragnar Kjartansson calls it a “feminine nihilistic gospel song.” He’s talking about his nine-channel sound-and-video installation in which musicians—playing instruments alone or in groups—are joined into an ensemble. The performance was filmed at Rokeby Farm, a 43-room estate in upstate New York. The inherent isolation of such a large estate, as well as the separation and then blending of the musicians, is purposeful. It’s a powerful reminder that during this time we are “alone together.” —E.C.