Not actually sure, but can't the person deny sending a delivery receipt? I know you can do that for emails, and text messages are essentially small emails...
It's a regular music playing app, with some nifty features. You can also upload music to the web version (http://music.google.com/), which you can access from the app... handy if you don't have a lot of space on your phone or tablet! Google Play Musi...
