I agree with the first poster - this application does exactly what it says on the box and is excellent if you need to start taming your music library - well worth the money especially if you have a large library.
There's a comment here about powerful features - in fairness I haven't tried the other product mentioned, but with the exception of actually going and searching for lost tracks from your hard drive for you (I don't know of any apps that do this) Song Sergeant had all I needed and more. I'm the kind of person who has little time and patience for messing with new applications for hours - I want them to reliably do what they're supposed to do cleanly and elegantly with the minimum possible effort from me (why I use macs :) ) - this is exactly what this program does.
I want to add another point - the developer is highly professional and committed to his product. I had a small issue when I first tried to use this application - Song Sergeant was working perfectly - it turned out that my iTunes library file had a corrupted entry. I'm no techie, so I had no idea what was wrong.
Not only was the developer immediately responsive to my support request, he also problem-solved and diagnosed the issue, examined the iTunes file, identified the problem entry and fixed the problem - very impressive when you consider that the whole thing was nothing to do with his product and was totally not his problem.
I just wanted to share this because this kind of professionalism should go a long way when considering applications that get in there and manage your precious music.
Highly recommend this company and the song sergeant product - thanks guys!