I apparently mis-read how mp3gain functions as far as tags are written and what they are used for. I originally used mp3gain to make all of my mp3s quieter for use on my iPod (I liked to use the EQ). Now, since I no longer have one, I am getting tired of all of my songs being very quiet on the PC or on my Cell.
Here is where I went wrong
Instead of using mp3gain/undo, I used mp3tag and deleted all related fields from my entire music collection. I was under the auspice that mp3 decoders read this information and made their adjustments from it (which is wrong, this is how replaygain works.)
What would be the best way to go about normalizing all of my audio files again?