If the boookstore is too quiet, it's not good because therre aren't enough customers. One of the reasons bookstores have musicians is to attract customers with good taste, and re-enforce their desire to come back. If you keep things too quiet (no laughter, no applause), the customers might think you're just a nice recording. The applause calls attention to the fact that you're a live act, shows how classy the store is to have you there, and helps business.*g*