iOS 14.5 won't actually let you change a default music service

Engadget 

It turns out that Apple's iOS 14.5 update won't actually let you change your default music service that you use with Siri. Beta users had originally noticed that it appeared as if early versions of the update might allow you to change the default service that launches when you ask Siri to play a song. This meant that rather than specifying a third-party music app with each request, Siri would remember your preference and launch with the service you had originally specified. While all that still seems to be the case, TechCrunch reports that Apple has apparently "clarified" that it "doesn't consider this feature the equivalent to'setting a default.'" That's because the feature relies on "Siri intelligence," which can track your music-listening habits over time and predict which app you're more likely to want at that moment.