If like me you have a big music collection gathered from lots of sources, then you are probably having the same problems with the awful metadata that some tracks have.

A lot of my tracks have weird or missing track details, errors and for some tracks I have no ID3 tags at all for the artist and album. I also have a lot of duplicates which have happened from mistakenly importing the same CD twice, or when I've added a friends collection to mine and they have the same track but with a slightly different filename, so it slipped through the net.

Given that my collection is continuing to grow, and I am increasingly accessing my library via other PCs, devices and my Xbox via Xbox Media Centre I decided it was time to tidy things up before it became an impossible task.

Below are the steps I went through, which I will now do with all new tracks before they get into my library.

Step 1 Tagging

Even if your tracks have been imported directly from CD the ID3 tags can still contain errors, especially if you are importing old CDs or non-mainstream CDs. The best tool I have found to fix tags is MusicBrainz Tagger http://musicbrainz.org/tagger/index.html. This great tool scans your various music files and writes clean metadata tags (ID3 tags or Vorbis comment fields) to your files.

For files that MusicBrainz doesn't recognize, MB submits acoustic fingerprints (TRM ids) of the files back to the server and asks the user to manually edit the track information, so that the next time someone uses the tool these tracks will be identified.

MusicBrainz allows you to set the threshold at which it thinks it has a match. For my collection I found that very few mistakes were made with a threshold of 80% and I was able to automatically update the tags on around 50% of my 8,000 track collection this way.

For the other 50%, MetaBrainz Tagger still made a pretty good guess as to what the correct tags were. In some cases I was able to automatically accept MB's best stab, but in other cases I had to use the tools within MB to find the correct details. This took quite a long time, but was worth the effort as MB helped me identify a lot of previously unknown tracks and artists. Sorting by album proved to be the quickest way to process my tracks as once I'd confirmed what album a particular track came from I could usually process another 10 tracks from the same album immediately.

Step 2 - Re-import to iTunes

(a) iTunes unfortunately manages its own tag database so it won't immediately pick up the new information. This can be fixed by:

- highlighting all tracks in the library, right clicking and selecting