[ Bug ] Changing genre for album incorrectly modifies artist for other songs

[SindreKjelsrud]

When a user changes the genre for all songs within an album, the artist of the first song in that album is unexpectedly applied to all other songs in the album, even if those songs originally had different artists.

Steps to Reproduce:

1. Select an album that contains songs from multiple artists (e.g., a compilation album or a soundtrack).
2. Go to the album editing interface (or similar function that allows batch editing).
3. Change the genre for the entire album.
4. Save the changes.
5. Observe the artist metadata for the songs within the album.