If you would be making a game, you should also probably check http://freemusicarchive.org/

Note it changed hands last year and is replicated at archive.org and soundcloud

https://en.wikipedia.org/wiki/Free_Music_Archive

https://archive.org/details/freemusicarchive https://soundcloud.com/freemusicarchive

That site gives me an error 500

I had the same thought :) The track "Driven" by "Blue Crystal Star" stood out to me in that regard.