Hi,
I'm wondering if there are any .NET libraries (ideally open-source) that deal with guitar chords (e.g. given either a chord or a set of fret/string combinations it can retrieve the corresponding fret/string combination or chord respectively).
I'm having some trouble searching because "C#" is a note and there is a concept of "programming" musically as well.
Indeed, it is hard to find something. I looked on sourceforge.net and only found a non active project called chorderator written in c#. The screenshots look nice, but I couldn't get the program to run on my system. Probably need to have Visual Studio installed or something. Hopefully you have better luck. In any case, there seems to be many chord generators on the web and sourceforge, not necessarily in c#, but something you could probably hack into c#.
Here is something done with Silverlight and its on CodePlex. Hope it helps.
It seems to me that you're actually asking for a collection of digitized guitar chords, rather than a particular library. I think that if you look for a guitar chord database, you will find several downloadable programs that incorporate a database, but I haven't found a freely available db of chords yet. Unfortunately freebase doesn't seem to include chords.
It may be that all chords are calculable based on a breakdown of their names. In that case you would want a library, or at least the formula, instead of a db. But I don't believe this is the case. There is some explanation of the naming here though.