Right now the AirPlay button in iTunes 12.2 disappears as soon as you connect to Beats 1, the new radio station that launched as part of Apple Music service. If you're accustomed to streaming music from your Mac to an AirPlay music source like AirPlay-equipped speakers, an Apple TV, or an AirPort Express connected to a speaker system, this might seem like a deal-breaker. But it's not.
Hopefully the disappearing AirPlay button is just a weird bug that Apple will patch in a forthcoming iTunes update. Until then, there's a fairly easy workaround. Just bear in mind that this sends all of your Mac's audio to your AirPlay speaker, not just iTunes.
First of all, if you've already told your Mac to send audio output to an AirPlay source, it'll continue to send the Beats 1 audio there:
How to send Mac audio to AirPlay speakers
You can also use the MenuBar to get Beats 1 over AirPlay.
- Hold down the option key on your keyboard.
- Click on the Sound menu. (If the Sound menu isn't active on your Mac, you can turn it on by going to the Sound system preference and clicking Show volume in menu bar.)
- Select the AirPlay source you'd like to output to.
