OK, this is a first. Local blues festival, getting pretty big. Usually about 4,000 people or so there at any given time. Two stages, one is used as setup while the other has a band playing and vice versa. So, we played it last year and everyone had a good time. We were invited back and played right in the middle of the afternoon. Good crowd. We get set up and halfway through our first song, our keyboard dropped between half and one full note! Across the board. It took a little while to figure out through the monitors who was so hideously out of tune, but there it was.... electric freaking keyboard dropping tune. In our band, the keyboard is a lead instrument on a LOT of our songs. Jerry Lee Lewis style stuff and lots of organ blues etc. So just not having keyboard is not an option. Anyway, since it is not a full note off, we have to tune the guitars and bass down by ear between songs to approximately match it's pitch. You can imagine how freaking professional that sounded. Had to do it after the first few songs before we were all out of tune to the same degree. Finally found some hamfisted solution with a backup keyboard about halfway through the set, so we quickly tuned up correctly and finished strong. But Holy crap that was a horrible way to open up in front of that kind of crowd! Naturally we get back to the house and the keyboard works like a champ. Only thing we can figure is that the long power cord supplied to the stage somehow didn't get enough amps to the keyboard and that is what caused it to drop tune. It has not had a problem since.... no word as to whether other bands during the festival had any similar problems, but that was a strange one. Nobody booed or threw anything at us, so I guess we explained the problem and handled it well enough to cover the problem.