I was looking for a site to download MP3 backing tracks for my PA800 and have had good luck with this one for $2.99. A lot of them are original tracks.

http://www.karaoke-version.com/en/

I would like to get other opinions also.
Bernie
_________________________
pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact