Audacity is the “gold standard” of open source audio editors. I use it only for simple editing, but it does the job.

For converting audio and video formats, by the way, ffmpeg is the standard tool. It’s a bit cryptic, but not too bad. The drawback is that it is in “perpetual beta”, so there are some things that are badly broken; for example, it incorrectly handles the AVCHD/H.264 video from my camcorder, such that if I try to convert to ntsc-dvd format, the video is half as slow as the audio. Hopefully the folks who hack on it will fix that soon. But for converting among wav, mp3, ac3, flac, and whatever else, it’s a godsend—and it does work reliably on native mpeg2 (e.g. DVD video) streams.

Anyone out there banging their head into the wall about the aforementioned ffmpeg problem, email me for a very-slow-but-simple perl script that will solve your woes.

I've used Cool Edit for a decade, but it was acquired by Adobe and I'm not sure what they call it now - it's a great editor and powerful processor as well, try it out from Adobe's website . . .

Another vote here for Audacity.

Audacity is available for Linux, Windows, and Mac OS X.

On an Ubuntu machine, type: "sudo apt-get install audacity" in a terminal window, and that'll probably do it.

You can use them to edit sound files: take out portions or apply effects to portions of an audio file (e.g., fade in/out, noise reduction), and save the result.

In a typical scenario, you could use a sound editor program on a recording made by a portable audio recorder device. You can delete portions you don't want to save (e.g., homilies and other miscellaneous noises :-) ) , and select the music performances to save as separate WAV or MP3 files.

I'll check out these programs. Thanks for the very helpful suggestions.

Francis, I am Mac also. I use Audacity.