Eli reminded me of an incredible story that John Baldwin had told me some time ago about the 10cc song "I'm Not In Love" - in which the band recorded an absolutely epic number of backing vocals through tape loops to create the ethereal sound of the song. For some reason I'd never looked up the proper Making Of Video to get further insight into the process but I highly recommend you spend some time with it... even if you're not a 10cc fan, it's a fascinating process.

Related: the entirety of the new Gayngs record.