I use iTunes match for that. I’m not sure if Apple still lets new people sign up for it, but you can have the master collection of your music on Apple’s servers

I use iTunes match for that. I’m not sure if Apple still lets new people sign up for it, but you can have the master collection of your music on Apple’s servers (there are some limitations on length (but not size, oddly enough) so the lossless single-file recording I have of Richard Strauss’s Elektra is marked ineligible, but otherwise they have my full music collection.