I've applied replaygain to some of my music. Now I want to get rid the replaygain, but I don't know which songs have them. Is there an easy way to remove it from all my music (it'll try to remove it from a song whether or not it has it)? I tried selecting all and right clicking and removing replaygain info. from my music, but that caused explorer to crash among about everything else.

If you want to easily find out the files that you have replaygained, just open up foo_dbsearch and search for %__replaygain_track_gain%. Then just select them and right click and remove replaygain info.

By the way, why do you want to remove replaygain info from your files?

Some replaygain is worse than no replaygain, but full replaygain is miles better than no replaygain.

Why don't you apply replaygain to all your files?

You can also do this:

<Extended Playlist generator>

Query: %__replaygain_track_gain% MISSING

->Generate Playlist

Then just Right-Click on the Playlist tab and 'Remove replaygain info'. I guess that if you have a large music collection and a lot of replaygain files, it will take some time and sometimes foobar seems to crash or hang, but it's just that it's working on it

Anyway, my advice is: replaygain all your files. It can't do any harm to your files

Sounds like a good idea. I just didn't want it b/c I didn't know if I did it 'right'. I have various formats I've encoded my stuff to, including mp3, ogg, & flac. Can I add it to all of those? Please let me know how. Thanks to the forum for always being overly helpful!

EDIT: I'm also curious about what modifications programs can and do make to music files. So far I've discovered they can have multiple different metadata tags (e.g.APEv2) and now replaygain (which doesn't mess with the actual audio, it just tells the player where to set the 'amp' strength?).

You can add RG to any file. IIRC if the format supports metadata/tagging, the RG data will be put in tags, otherwise it will be stored in foobar's database.