simplest way is to
convert the songs to wav files.
open the wav in a wav editor turn the vol up a little in the file. save the wav, don't save as, just click save.
do that for all the wav files.
then convert them to mp3 or ogg or flac what ever you want because once you adjust something in the file while it is a wav all drm is gone,
and it is now your file it won't be the same as online.
if it is wma that can be a good thing because most wma's are,
compressed way to small at them online stores and that messes with the sound.
most the sounds get messed up by the poorly done online store wma's are in the genera's of disco , rap, and anyother genera that has the same type of wild beat going on in the background while the singer is trying to sing.
but thats aready posted in the forum in my other messages.
roving cowboy / keith hall.