Google Play Music is officially available for Glass Explorers
The announcement came from Stephen Lau, who has mentioned a few different times on Google+ he was involved in bringing music to Glass Explorers.
Explorers can visit their Glass page and find the option to install Play Music in the Glassware section, or by using the MyGlass app on an Android device.
In the few minutes I have experimented with it, I have to say it doesn’t run as smooth as the sideloaded APK did. Hopefully the release is to blame and the kinks will be worked out here shortly.