I hate when my music library drifts over time.

Example:

- Add "Phantom of the Opera" to my library
- 3 years pass
- Now there's 5 "Phantom of the Opera" albums in my library, each with only a partial set of songs.

I guess the mistake here is calling it _my_ music library.

It's not mine. It’s Apple’s.

What’s mine are the pointers to Apple’s music catalog.

Apple (& rights holders) get to decide what constitutes an album — now and in the future.