fix mp3 replay gain (AKA normalize) quick and easy

Some things are SO much easier on Linux than Windoze. Don't need an audio editor, even an open-source one like audacity to perform this routine task on Ubuntu.

sudo apt-get install mp3gain

dir=/music/EckhartTolle-StillnessSpeaks
 
# fix replay gain for all songs in $dir
for i in `ls -1 $dir`; do mp3gain -r -k $i; done

where:
-r: radio mode: apply track gain automatically
-k: prevent audio clipping