Quick guide: iTunes Radio vs. Pandora vs. Spotify vs. Rdio vs. Google Play Music
2. Google Play Music
Google beat Apple into the online music streaming business when it launched Google Play Music in May. The service lets you listen to music from Google's library without ads, store up to 20,000 of your own songs online, and access music anywhere without having to syncing your devices. In a stab at iTunes, Google Play Music also has a system that lets you buy new music through its interface.
Cost: Google Play Music's standard version is free, though the sign up does require you to enter credit card information, making it easier, and perhaps more tempting to purchase a few songs as you listen. The All Access version, which lets you create personalized radio stations and listen with unlimited song skips, costs $9.99 per month.
Sharing: Google Play Music makes sharing easy via the Google Plus social network.
Limits: To get Google Play Music to recommend songs, you have to pay, unlike with Pandora and Spotify.
Devices: Accessible via play.google.com. For Android and iOS devices, you have to download the Google Play Music app.