I need some help understanding/organizing my music files.  Background:  Originally used Sony's Sonic Stage and ATRAC files on Sony's Pocket PC.  Then because Sony's format was proprietary and could not play on anything else, I was advised the best thing to do was to reload all my cds into Windows Media Player, which would allow me to download the music into an iPod or other type player.  So I relaoded all my cds manually to Media Player.   Then since I purchased a new iPod, I used iTunes which took the music from Media Player and converted it.

What I'd like to do now is elinimate the music files I am not using.  I could delete all the files in Media Player, and just keep the ATRAC files for my Sony player and the iTunes files for use with my iPod.  But then I lose flexibility of Windows Media player to keep the files in a flexible storage format.

Does anyone have any advice or suggestions on improving what I am doing?  Thx.