TCA smells nasty, like a moldy newspaper. Its effect on astringency demonstrates the role that fruit aromas play in creating the illusion of harmony. Consider for a moment the difference between music and noise. At the beginning of a symphony, the instruments quietly tune up—a most obnoxious sound. Then they strike up together, with much greater volume, and we are carried away by music, for which we have a very high decibel tolerance as long as we are emotionally taken up. One false note, though, and we wince.
