Our corporate cousins at AOL have a new tool for enjoying and sharing your favorite songs: the free Play app. First introduced at SxSW as an Android-only offering, it's now available in the App Store for iPhone.
Play meets the table stakes for a social music app by allowing you to play songs from your onboard music library; you can comment to Twitter or Facebook about what you're listening to, complete with location info. If you want to keep track of your friends who use Play, their comments and song history will appear in the app's Feed section.
For music discovery, you can sample your friends' favorites by listening to excerpts on Rdio or iTunes; but there's actual free music in there, too. The album play section includes songs from SHOUTcast Listening Party, MP3 of the Day and other sources.
If you're in the mood to share and chat about your music, and Ping's not your thing (nor Soundtracking), check out Play. If you want a more full-featured player without the social bits, take a look at Panamp.
Note: TUAW is an AOL brand.