Freegal Music gives you access to hundreds of thousands of songs in the Sony Music catalog. You can download up to 3 songs a week for free with your library card (the weekly counter starts Sunday night at midnight). Songs are in DRM-free MP3 format. You can also stream music through Freegal for three hours every day.
Freegal also has a mobile app:
Please note: In the iOS version, songs are saved in the app, not your iTunes Library. To add a song you download with the app to your iTunes Library, you must download it on a computer within 2 weeks of the original download. Learn more in the Freegal FAQs.