To me, pipe-organ enthusiasts...
Aine O'Dwyer's 'Music for Church Cleaners Vol 1 and 2' on MIE
[video]
https://www.youtube.com/watch?v=ZdKFD4lqUGY[/video]
An improvised recording made on an organ in a London chapel while the church cleaners go about their day, Aine's timeless music is constantly offset/ enhanced by environmental noises around her as she plays: the drone of the cleaners' vacuums, the clacking organ pedals, the creaking of the pews, random noise and chatter.
Anyone allergic to religious-sounding music will probably find it too much, but for fans of Nico or Dead Can Dance gloominess it's an uplifing and satisfying listen, with the LP landing somewhere between an ambient meditation, a live improvisation, an archivist field recording, and something completely other. 
500 run sold out at MIE, but still up for pre-order at Boomkat: LINK