How to upload music to a new iPhone

I have an iPhone 6s and just upgraded to the X-R. I have about 6000 songs I want to get on my new phone. Many are from old CDs so not downloaded from cloud. The library where my music is stored is on an old computer running on windows vista. (We are about to replace it) Therefore I cannot download a new version of iTunes to transfer the music. I really don’t want to lose my music as I have cultivated it over decades and have really serious playlists. The music is the whole reason I’ve stayed with iphone at all. how can I get my songs from old phone directly to new phone? Please help!