I want a little player that will let the user change the sound track playing in
the background I have nt really playedwith sound in Flash I was going to just
use gotoAndStop to do it but Im sure there must be a more effecient way????

don't use gotoAndStop(). that's a movieclip method.

you should use the Sound() class for more complete control of your sounds.
check the flash dictionary for all the methods related to the Sound() class.