Help recognising an SF novel

On behalf of a friend of a friend...

A friend of mine is attempting to find a SF novel for a friend... but the friend can't recall the title or the author... all he can remember about the book are a few sketchy details:

A SF novel...
in which people can leave their bodies, but they are in danger of being caught by rotating objects like fans and thus trapped in this state forever... and this activity is frowned upon by those who can't so they set out to intentionally trap those who can... not a hope in hell I think
There was a love story involved, and a rebel group who practised this activity... and the protagonist wasn't exactly a rebel but was in love with a girl who was... and IIRC basically opted... to remain in the OOB state at the end of the book. The fear of those who fought against them was based on the thought that these out of bodies might be anywhere and no one would know.

Anyone any idea?

ETA: kerravonsen has identified it as On Wings of Song by Thomas M. Disch. Amazing. Thank you kerravonsen!