I have two front jacks, one for the DVD-R and the CD-R drivers.
I'd like to use my headphones when I'm listening to my music that is
already on the harddrive but I don't like the idea of using the rear
headphone/mic jacks just to plug in a pair of audio headphones.
Besides, I don't like the thought of bothering other people in the house
by using the speakers that came with the computer (It's a Dimension 2400.).

How would I be able to hear my music through one of the front jacks?
Which front jack do I use for that?