The problem with many digital music libraries is that they're a disorganized mess, compiled from multiple sources over the years. Ripped from CDs. Downloaded from dodgy P2P services, bought from iTunes, Amazon, etc.
And as we're approaching a world where all this stuff will be stored and/or accessed from the cloud in one fashion or another, the need to categorize existing libraries properly is going to become more of a necessity than it is today. This is particularly true for the kind of "scan and match" digital music locker services that aim to match music in users' hard drives against the same songs on a centralized server. If the service can't understand the file, it can't match the song.
Enter Rinse, a new tool from RealNetworks that aims to clean up the metadata in users' libraries. It bills itself as "song organizer" that adds missing album art, fixes misspellings, removes duplicates, renames genres and so on. So for instance, for those of you with different entries for Guns N' Roses vs Guns n' Roses, Rinse will combine them into one entry. That sort of thing.
The software can either fix entries automatically, or give users the option to edit any proposed changes. Rinse costs $40 and is available for both Mac and PCs, with a free trial for up to 50 tracks.