Upgrade & Afterlife

Across their career, Gastr del Sol — the duo of former Bastro and Squirrel Bait member David Grubbs, and solo tape composer, producer and all-around experimental-music maven Jim O’Rourke — jumbled together their many far-flung influences into a sui generis union of avant-garde sonics and more conventional song-based moves. Upgrade & Afterlife was in some ways their most difficult release, but its shadowy depths nonetheless contained numerous unconventional pleasures: the glitched-out drone of opening track “Our Exquisite Replica of ‘Eternity,’” the gradually blooming prog-meets-post-rock of “Hello Spiral,” the ghostly electroacoustic wash of “The Sea Incertain” and most enchanting of all, an epic cover of John Fahey’s “Dry Bones in the Valley” featuring mesmerizing violin textures from minimalist pioneer Tony Conrad. Music this weird has rarely felt so warm.