TuneUp is an iTunes plug-in for Windows users which helps you analyze, clean up, and correct track tagging SNAFUs in a fraction of the time it would take to do them manually. The interface shows up to the right of your iTunes music library with features for cleaning tags, finding album artwork, getting more artist info, and genre-related recommendations from Amazon. You can also search local concert listings on StubHub for bands in your library.
The Clean tool takes an audio fingerprint of a mislabeled song, matches it against Gracenote's Global Media Database of more than 90 million songs, and returns most likely matches which you can save to your library. It even recognizes songs from the same album so you can get both music and cover art in one pass. In our testing, it worked almost flawlessly as long as we only chose groups of 50 songs at a time, but simply selecting the entire library and trying to clean it all brought the program to a crawl. The Cover Art tool quickly offered covers for every artist it recognized, and the Now Playing section offered up music videos for the artist playing, all accessible with a click of a button.
TuneUp Companion isn't perfect, but it's a good start. As a beta release, there are still bugs to be ironed out, and a Mac client is due soon. The trial version offers 500 "cleans" and 50 cover art "finds"--not nearly enough for most libraries. An unlimited version of TuneUp Companion costs $19.95 for a one-time charge or you can get an annual subscription for $11.95.