So if Spotify creates a music recognition feature that competes with Shazam, would they need to create an API that allows you to choose your music recognition service from within Spotify? This a very slippery slope!
Probably not. Someone using Spotify and their hypothetical music recognition service is more like someone using Google Search and Gmail which isn't a problem. This is more like is someone would search Spotify and artists from their own record label (or promotion company) were at the top of the search results.
Spotify is close to the 50 or 75% threshold. So would they also need to include Shazam's advertisements within their own app? Cause otherwise Shazam would still fail. I'm not understanding how this can work practically.