@djsundog Alright, you asked for it.
https://github.com/zigg/fediplay
It works! Anything tagged #fediplay, the client will grab the first URL (hopefully avoiding mentions and hashtags), download it, and play it.
Any new songs that come in while it's playing music are downloaded immediately and queued.
There are NO CONTROLS. This ride is on autopilot. 😎
PRs are, of course, welcome. @viciousviscosity had the idea that ffmpeg might be able to stand in for afplay on non-macOS systems, but I ain't got time for that.