Apple Music has some 40 million tracks, and has become one of the leading music streaming services. The promise of Apple Music and iCloud Music Library was that you can mix your personal music library with the music in the cloud, and create a seamless listening experience.
In practice, this is problematic. iCloud Music Library screws up metadata, not only on your own files, but on its own files after you add them to your library. (Here’s one example of how this happens.) As such, I strongly recommend that anyone with a carefully tagged music library avoid using iCloud Music Library.
However, there’s nothing stopping you from using Apple Music. You’ll be able to play music from Apple’s cloud, but the only thing you won’t be able to do is add that music to your library, or note which tracks you “love.” This is a small price to pay for saving your music library from destruction.
All you need to do is turn on Apple Music, but not turn on iCloud Music Library. In iTunes, you do this in the General preferences:
And in iOS, go to Settings > Music, then turn on Apple Music, but don’t turn on iCloud Music Library.
If either iTunes or your iOS device prompt you to turn on iCloud Music Library at some later date, just say no.