Let's say, you're writing a music app. Something like Apple Music, Amazon Music, Spotify, or whatever. You will, of course, want to offer your users multiple ways to find music. A flexible search interface, a list of songs, a list of albums and so on. The fun comes if you decide to offer a list of artists. When should an album show up under a particular artist? How do you handle ensembles that aren't publishing as a named entity (i.e. it's by a bunch of people and not "by a band")? Worse still, how do you deal with tracks that include a featured guest artists on an album that is otherwise by a single person or band?
As a programmer whose cares about users, my vote would be to accept some duplicate presentations due to fuzzy matching rather than risk disappointing a user who disagrees with my way of answering those questions. But that doesn't seem to be what Apple picked. Indeed, I simply can't deduce the logic (if any?) underlying how Apple Music handles these questions. In the album list one album can show up more than once, partitioned according to the performance credit for each song. An album by a band that has one song with a featured guest performer isn't enough to make that band show up in the list of artists.1 WTF, Apple? What are you thinking? Just ... WHY?!?
1 I've ripped the True Love Never Dies from CD, but Otherwise doesn't show up in my artists list, because I only have that one album at it has one track featuring Ash Costello. Grrr...