ChordQL

ChordQL is the query language associated with ChordML, used to search for music containing particular note/chord sequences.

It's rather hard to get information on by Googling, because there's a software package called "Actos" connected with it, and Actos is also apparently the name of a medication, and as with most medication names there is a whole host of sleazy spammers trying to promote "Buy Actos Now!" sites by spamming the search engines with every conceivable keyword that might be connected with that. Their dumb spambots seem to have found that the term "ChordQL" is sometimes associated on the Web with "Actos", and hence added snippets of text using that term in their sites to be picked up in a search, thus overwhelming any actual sites about ChordQL that may exist (which seem to be dwindling; the project may no longer be active).

Links

 * Sample ChordQL queries