Hello crofty,
There are many programs out there which can edit ID3 tags. All you have to do is do a simple google for them. One of the programs that I have used is
--ID3-TagIT--. Back in the day when I started to clean up my MP3 files, this program worked flawlessly. It let me do single and multiple ID3-Tag changes, and for your needs, it specifically states (on the front page of the website) that it supports batch editing.
Other programs that are available which do what you need are as follows:
Also, I would recommend you do a forum search as this topic has been discussed many times in the past. To start you off, here are 6 search results:
In the future, when asking a question (just to let everyone know that you have done some prior research), stating which programs you have been looking at, or have already tried would definitely help us answer your question more directly. We could help you by showing you how to properly use a program (if, for example, you were not sure on how to batch edit with a specific program) or we could give you our thoughts on programs that the both of us have used.
Also, as many of these programs do the same thing, just in a slightly different way, it could just be personal preference on which program someone thinks is 'The Best'. So, after all is said and done, I would try out some of the listed examples and then you can determine, on your own, which program works best for you.
If you have any other questions or concerns, don't hesitate to ask.
Raven