Well yes. If you want to play mp3 files, just look at MusicPlayer.cs file, all you need is there. Also look for some tutorials, is nothing special. If you want the gesture part, look into Program.cs file. I don't use the built-in gesture detection of Leap driver, I just use the basic data returned by driver, like X-Y-Z finger position, number of fingers, hands, etc, and do my own processing and gesture determination. I did not included the User Interface part , just the code behind.
The code is really crappy, I hope you will understand something. Enjoy.