Selfhosted

Mpd + a frontend of your choosing, I prefer ncmpcpp, will run on just about anything and is remotely controlled through apps or ssh. Mpd is great when the server is physically connected to the audio output device. I use it to remotely control a speaker connected server that can also run Plex (because I prefer plexamp for streaming and syncing to my phone, other android devices, and smart speakers). They both look at the same directory of a collection near 30 years in the making with hundreds of thousands of files and a wide array of formats.

I use Jellyfin with Finamp on Android/PC and the Jellyfin plugin for Kodi on my HTPC.

The Jellyfin plugin does movies/shows too and not just music but it handles music playback as well. For a dedicated music box I'm not sure if I would use Kodi for it.

MythTV for the main storage, stored in folders by my genre.

All metadata updated via Picard.

Syncthing to replicate to a Raspberry Pi (2 or 3, I don't recall which) running Volumio with a DAC board to connect speakers to.

The Pi is in the bedroom, so I only replicate the genres that I want, which cuts down on storage needed on the Pi, and means I don't need MythTv / NAS / etc. powered over night.

I like using rygel currently, just run it by command line and media folders are available over the network. Any device with VLC can see it on the network and play.

My problem is that I cannot find a selfhosting solution that has the nuts to spool up 80k+ hi-res, original sourced, flac files that reside on two 10TB drives through my ancient technology. MusicBee is the closest thing I've come across, but that is local, and it struggles. I stay around the compound now days so local is ok, but it would be nice to stream out on the back porch without cranking my stereo to 11 so I can hear. I have bluetooth options but range is an issue.

local storage server as a backup and to download my music to my devices (ik jellyfin is better then this but i already had the storage set up)

Emby. It is so far, the nicest music client on iOS that I’ve been able to find.

I got 500 gb drive pcloud with my pia socket 5 proxy/ vpn and i can play music files in their app so i put my flacs there.

Have always preferred Emby. Have been running it for around 8 years.

MPD (Music Player Daemon) would be perfect for that old Autonomic - super lightweight, runs on practically anythng, and Symfonium is an amazing Android client that supports it natively.

I use Funkwhale, which I have liked, but my use case is just streaming music through my laptop and listening with headphones. I don't think there is a client available that will run on your Autonomic streamer.

Funkwhale does have a subsonic API, so you could use a subsonic client, but you mentioned that didn't quite work before. (Is that what you mean by __sonic? I haven't actually heard that term.)

Funkwhale is nice, but I think for most people it doesn't (yet) offer any useful features beyond what Navidrome has, and probably even lacks a few things that Navidrome has. Funkwhale's main appeal is that you can follow someone's music library via the fediverse, although there hasn't really been a lot of use for that so far. Version 2 is coming soon, though, and adds a whole bunch of new fediverse features.