I did a search on the board and did not find any references to a device called a chord capo. I just viewed an ad at the site below and was wondering if anyone on the board has ever used one of these. In theory, the device allows you to set and fix a chord on the first four frets rather than bar an entire fret like a regular capo. Your left hand is then free to finger other chords or individual notes on the remaining part of the fretboard. It allows you to quickly change keys by alternate tunings of a base chord. It looks pretty nifty and I can imagine having fun with it but I have never seen one in a shop or played one. I can imagine it would be handy with slide guitar. Here is the link to one called the Voice Capo:
http://www.voicecapo.com/
Mike
http://www.voicecapo.com/
Mike