Every so often, Google reminds music rightsholders that it has invested tens of millions of dollars in YouTube’s Content ID copyright protection system – usually in response to criticism of its anti-piracy efforts. But Content ID isn’t the only game in town for spotting unlicensed music use on YouTube. Music licensing firm Audiosocket has been getting headlines overnight for its launch of something called LicenseID. The technology works by embedding ‘tags’ into audio files, then tracking where, how and by whom they’re being used. The theory is that while Content ID can identify a piece of copyrighted music, LicenseID will provide more granular information on whether that music has been legitimately licensed. Music licensing library SourceAudio is the first customer for the new technology, but we’ll be interested to see how YouTube responds, in terms of licensing LicenseID or adding similar features to Content ID.