Your interest and involvement
I am the maintainer of the Subsonic snap
The Subsonic Music Server Appliance would be targeted at home users.
There is a snap for Subsonic: https://snapcraft.io/subsonic-arubislander
Optinally, for easier discoverbility on the local network, the avahi snap could be installed alongside: https://snapcraft.io/avahi
Subsonic is a java application that should run on all supported platforms. When used as a server there are no additional hardware requirements. When run as a jukebox, audio out would be a requirement.
Some form of (external) storage is desirable to hold the media library.
Apart from some autoconnected interfaces, the removable-media interface is consumed by the Subsonic snap. This would need to be autoconnected in the appliance.
The snap is regularly updated to incorporate security patches and updates to the Ubuntu packages the software depends on. Upstream for Subsonic is also monitored regularly.