Stuff about Music
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You don't really need to normalize the gain of your library with MP3Gain, but it's there if you want it. The most trouble you have is when MP3s get added to the iTunes library their different levels get exaggerated. So within iTunes, select the song, Get Info->Options->Volume Adjustment.
If you've bought a song at the iTunes store, but need access to it elsewhere:
- Use QTFairUse (be sure to bring the config file up-to-date with the version of iTunes) to convert from m4p to m4a.
- From iTunes, go into Edit->Preferences->Advanced->"Importing" tab->Import using mp3 encoder, choose your bitrate, then apply the changes.
- Select the .m4a files in your library click Advanced->Convert selection to .mp3
Some songs, like Ayumi Hamasaki's Monochrome (Ayu-chan, what the hell was that?) require editing. Audacity's Fade Out goes a long way. Don't forget to use lame to export from Audacity to MP3.
Huzzah!