“Library music” is the audio equivalent of stock footage: instrumental pieces written for the express purpose of being licensed for background use in movies, TV, and radio. As with seemingly everything else ever recorded, library music has become something of a fetish item for listeners who’ve heard it all and are scouring for new-old kicks. The Library Catalog Music Series from indie label Asthmatic Kitty, home of Sufjan Stevens, pays homage to those mostly forgettable works, albeit in tongue-in-cheek fashion: These are as much experimental tangents as they are attempts to provide station-ID beds or soundtracks for industrial films.

Volume 4: Music For Insomnia is the most aggressively outré of the new batch, with label head Lowell Brams and helpmates Stevens (his stepson) and Bryce Dessner (of The National) piling on percussion and billowing instrumentation. It’s occasionally lovely, though it’s more interesting as a diversion in the Stevens and National catalogs than on its own. Roberto Carlos Lange, who fronts the Brooklyn band Helado Negro, offers something more straight-up ambient on Volume 5, as with the endless slow-mo violin of “Love 1.” Volume 6: Music For Savage Tropical Imagery, from Ex-Crystal Skulls member Yuuki Matthews, is the closest to the kind of cheesy ’70s analog-synth stuff most beloved of the folks who sample original library catalogs: bloopy, lo-fi sketches long on atmosphere. With library music, anything goes, even as little of it sticks.