Volumio is a great, Linux based, open source music player for Raspberry PI and x86.
archive.org is a non-profit library of millions of free books, movies, software, music, websites, and more.
They offer a really big collection of audio files, especially music like The Great 78 Project. Via their API it is possible to access their database from Volumio.
I'd like to start to get this two pieces connected.
This project is one of its kind!