Best way to develop a mp3 player using php and mysql and ajax

Hi there,

I am curious to know are there any good php tutorials out there that can help me develop a mp3 player only problem i have no idea where start ive been told i most likely need a function to list all songs in a folder and then basically have another function to calculate the length of the song aswell as play the next song in the in the folder or play list that wouldnt change and still playing as the user is moving to and from different pages of a website,

Is this possible as i am not sure if this is possible or maybe some-one if some one can give me abit of a hand with this or point me in the correct direction as im been looking for one but there r too many and as i am wanting a fully functional one writen in php to read from mysql database i dont want to have to include any other extra files that arent needed to get going as i have seen so many others heaps of them have a lot of includes which arent really needed,

So if you can help please let me know,