On its first album in four years, My Morning Jacket continues to explore different genres, jumping from alt-rock to folk to soul to pop. In the past, the Kentucky band has recorded in a grain silo and a church gym to provide frontman Jim James with heavy vocal reverb. The Waterfall sessions found the singer laying flat on a couch while recovering from back surgery. The opening track, “Believe (Nobody Knows),” bristles with an 80s prog-rock feel. That retro approach is used most effectively on “In Its Infancy (The Waterfall),” with its 70s keyboard tones and sonic wash of multi-tracked vocal harmonies. The fingerstyle guitar arrangement of the navel-gazing ballad “Like a River” is a cool draught for fans of James’ acoustic side projects. The 180-gram vinyl edition includes a download code for four bonus tracks: the solo acoustic “Hillside Song,” the loping soul of “I Can’t Wait,” the Lloyd Cole styling of “Compound Fracture (Miami Jungle Version),” and the stripped-down demo of a soul ballad that closes the album, “Only Memories Remain.” The Waterfall is beautifully engineered and seductive, even if it’s hard to shake the feeling that James may have been laying down on the job.