I thought this might be useful: maybe it could be added to the Tools FAQ.
mp3DirectCut is a free MP3 editor
The important feature is that it edits MP3 without reencoding; it just works on MP3 frames. So there is no quality loss no matter how many times you edit and save, and it's very fast.
You can cut and paste and change volume. If you want to do things like noise filtering you have to use a full audio editor, like Audacity.
Important setting: it does have its own basic tag editor, but only ID3v1.1.
Go to its menu Edit/Tag ID3 and tick "Keep ID3v2" and then it will preserve the tags thereafter on saves and you can do all your tag editing in MP3tag.
After you do your edits you need to use "Save complete audio", and the default is to overwrite the the original file. (Just "Save" saves a project file, a cut list, not a new MP3 file, useful but not what you normally think of as "Save".)
Just open and "Save complete audio" is often useful to fix glitchy MP3 files.
It has a comprehensive help file, which you really need to read since the controls aren't very intuitive.
So I have it set up as an mp3tag "tool":
Set Path to wherever you installed, e.g. D:\mp3DirectCut\mp3DirectCut.exe for me
and Parameter to "%_path%"
I set it as my "Default tool" and "Special program at double click".
It also acts a simple MP3 player, so I don't need anything else.