I've noticed that when playing I often bend the string of my guitar to put it in tune a little better, or what I think is a little better. Since I've started playing around with piano tunning I find I have a harder time tunning my guitar by ear. I used to tune in perfect fifths before but now I've learned that on a properly tuned piano there is no such thing as a 'perfect fifth'. Which left me to believe that one doesn't tune a piano but one untunes a piano. I think that Bach messed us all up by bringing about tempered tunning. He missed the great controbution that he could have had to western music, that is, adding more notes to the cromatic scale or suggesting that one have different tunnings for diffent keys. Lets face it, blues and folk music sound better in 'mean tunnings'. Tell that to you snooty ol' piano teacher.