Sometymes Why, the trio of Kristin Andreassen, Aoife O’Donovan and  Ruth Ungar Merenda, makes ethereally lovely music with an unexpected bite. The willowy siren-song sound of Your Heart Is a Glorious Machine belies the earthier sentiments it carries—not that it’s possible to ignore an album opener (“Aphrodisiaholic”) that begins with a couplet like I‘m gonna take you home and have my way with you / This’ll be a memory that’s gonna stay with you. In addition to its own supple songs, the threesome strips Concrete Blonde’s 1990 alt-rock hit “Joey” down to its yearning core.