From scratch to an android music player in 40 minutes flat. Basics like play pause and stop will be covered and if time permits, fancy buttons, rewind, fastforward, a seekbar, shake-ur-phone-to-play n even more
If you wanna hack along, get a laptop with the android ADT bundle downloaded n set up. http://developer.android.com/sdk/index.html
Knowledge of java and OOPs is very helpful.