This looks like the fastest and most capable application for this task that I have found and I tried several. My 17,000 song library is a monster to tackle since trying to recover from an external hard drive failure and merging various iterations of the library.

The problem is I would love to see how it handles deletions, etc but since I have not received a registration code despite paying for one several days ago I have no idea.

I would politely suggest a service such as eSellerate or the like to automate the issuance of registration codes so customers can immediately start using the software they've purchased.