Also like the main Android version, there's a so-called CD Listening Party feature that opens up free, complete albums, with selections changing weekly. (Naturally, you can also use the app to listen to your own MP3s stored locally on the device, but you probably gathered that.) Play will be available as a free, ad-supported app, though you can also get an advert-free version for 99 cents.
ENGADGET: AOL redesigns its Play music player app for the Kindle Fire, premium version is free Thursday