Apart from the illustration I also work for musicplayr.com as a Screen Designer. All the 16x16 pixel icons were done as vector icons so they can be rescaled for other purposes. The design principle was to keep it simple, understandable and without gradients and effects.
To further explain the functionality of musicplayr a special "Learn more" page was designed with some more icons:
I also created the simple Logotype with the playbutton replacing the "a", some Images for the different releases and a bonus pic. Check out musicplayr.com - It's simple and free.