Federico Viticci:

Apple has released iOS 8.4 today, bringing a redesigned Music app with Apple Music support, audiobook listening features for iBooks and CarPlay, and iBooks Author textbook support on iPhone. […]

iOS 8.4 is available now through Apple’s software update. Beats 1 will debut today in Apple Music for all users today at 9 AM PT.

Unfortunately, I won’t have time to update my devices until later tonight or tomorrow.