Beats 1, Apple's non-stop Internet radio station hosted by celebrity DJs, has made its first appearance in latest betas of iOS 8.4 and iOS 9 which are available to developers.
The Beats 1 interface appears unfinished with many features not active yet or performing erratically. Still, I was able to use the Music app on my iPad running iOS 9 Developer Preview to access a new Radio tab and get to Beats 1. I also browsed a list of stations and even streamed select ones and heard the promotional Beats 1 broadcast.
Here are my screenshots.