"You noticed what happened at the end, he added a little something extra at the end. This happens over and over in music," said Dr. Broyles, "what you heard there is simply a 'coda' and we'll refer to this quite a bit. All it means is at the end of a piece or a movement where the composer adds an extra ending of some sort".
Dr. Broyles went on to discuss two other musical forms which expand the binary form: the "rondo" and the "theme and variation".