Sit on your bike seat. Can you put one foot down on the ground? YOU'RE DOING IT WRONG. That's what they told me anyway.
Common sense tells you that when you come to a stop on your bike, you want to be able to quickly put a foot down so you don't, you know, fall over.
But apparently that's crazy talk. You're actually supposed to be able to fully extend your leg when the pedal is all the way down, to get full use of your leg muscles, because pedaling with your knees always bent is like duck-walking a footrace -- you're not fully using your muscles, and the other racers will laugh heartily at you.
Unless you are holding a guitar.
Since the pedal is several inches above the ground (or it would scrape it), that puts your foot several inches above the ground when your leg is fully extended -- which means you can't put your foot down. If your seat is at the proper height, and you come to a stop and try to put your foot down, you will fall over, and the other bikers will laugh heartily at you.
The guitar isn't going to help you here.