Users on Reddit may have found an exiting—but unlisted—feature of iOS 14.5. When asking Siri to play a song, artist, album, or podcast, some users have been prompted to select which service they wish to play it on, with a list of the installed music or podcast apps.
The process is simple, but inconsistent. Just have iOS 14.5 beta installed and ask Siri to play a song or artist. Siri will prompt you with a list of available services to choose from. After selecting one, Siri asks if it’s okay to access your data from that app. Agree, and your music or podcast plays on that app. Further requests to play music or podcasts will then automatically play on that app.