Great work!
Very well done. The NGAP has impressed me quite a bit.
The fact that the player loads the songs quite quickly (depending on one's connection speed of course) is astounding.
It's style is very simple and easy to understand, and not overdone graphically, and the colors used are easy to look at without straining the eyes.
What is very convenient is the fact that a help button is there for those who may have trouble with the player's functionality, including a list of keyboard shortcuts. Many people who create an audio player many times forget to add a help menu in the event that a user cannot figure out a problem that he/she has encountered with the player. Good job on that.
The button sounds are good but something that can be easily overlooked, as they're not consistent on all the buttons. The main player buttons (play, pause, load, random, etc.) are the only ones with sounds. A nice add-on would be to add that to the rest of the player buttons as well, perhaps using a different type of sound for the sliding buttons and sliding menus.
One thing I did notice though that caught my eye though, is a minor typo error in the help menu, under the "Not saving?" sub-category. The word unlimited is spelled with two "m's". Not that big of a deal, but worth fixing if upgrading the player.
Overall, excellent job, 10 out of 10! I hope to see more work like this from you in the future.