What Will We Expect to See in iOS 8.4

It's only a few weeks before the WWDC 2015. Apple has a very good habit of launching new iOS and operating system for Mac OS, so chances are that we are going to see the iOS 8.4 in June.
When the iPhone users are wondering why the jailbreak of iOS 8.3 hasn't come out yet, the new iOS is about to land on iPhone, iPad and iPod touch. So iOS 8.4 may be the target of jailbreak other than iOS 8.3 as the update between the two iOS is too short.

source: http://9to5mac.com/2015/04/13/hands-on-ios-music-app/

The music app in iOS 8.4 added Playlists and Radio Sections. In Playlists section, users can also see the More option at the upper right corner, and also the Recently Added at the top. In Radio section, people will be allowed to see recently added stations and featured radio stations from Apple, but users don't have options to view their saved radios.
iOS 8.4 won't bring many new features to the devices, because Apple focuses on the bug fixes ever since the release of iOS 8. But from the beta version of iOS 8.4, we can see the changes in the Music app. The new music app will add new features, such as More option, Three Dots option and several other options which is similar like iTunes on Mac. The More option is at the upper right corner of the Music app, and it enables users to view more recently added songs; Users will also see three dots attached to each song. By tapping the dots, users will see a menu comes out from the bottom, which provides users several options such as Play Next, Add Up to Next and so on. With this menu, users are able to manage their playlists easily.
Audiobooks is no longer supported in the Music app in in iOS 8.4, they are moved to the iBooks app of Apple. A few changes are also applied to the iBooks app. The app added a separate audio player for the audiobooks, which is more simply designed than the Music app. In this app, users can view the name of each chapters of the audiobooks, and select the chapter to listen to.

source: http://www.techradar.com/us/news/software/applications/ios-8-4-update-may-feature-beats-based-music-service-1284109

In the beta version of iOS 8.4, people still haven't seen the new Beats music streaming service. The new music streaming service isn't named yet, and it may still carry the name of Beats. The music service is based on iCloud function, so it will be charged, of course. Even though the Beats music streaming didn't show up in iOS 8.4 version, people believe that the service will come out in an official announcement.