How do I get out of the Genius Playlist?

Try force closing the Music app. Go back to the home screen, double-tap the home button, locate Music in the list at the bottom, tap and hold it until it wiggles, tap ➖ to close it, tap the home button again. Try Music again.

Do you mean the Genius playlist in the music app using iTunes Match? If so, you should be able to just tap the Playlists back arrow on the top left.