Apple today seeded the second beta of iOS 8.4 to registered developers for testing purposes



From MacRumors:

Today's beta is also the first iOS 8.4 beta to be made available to public beta testers. The beta, build 12H4086d, is available as an over-the-air download and through the iOS Developer Center. iOS 8.4 introduces an all-new Music app, which has a revamped design that shows pictures of artists in the Artists view and offers personalized playlists. It includes a new MiniPlayer, a redesigned look for "Now Playing," global search capabilities that make it easier to search within the Music app, and a streamlined design for iTunes Radio to bolster music discovery.

  Apple Seeds Second iOS 8.4 Beta With Revamped Music App to Developers and Public Beta Testers