Those rare musicians who have "perfect pitch" can name any note just by hearing it. And those with the most perfect of perfect pitches can name any chord, which is a bunch of notes played at once. Hearing and knowing, for example, middle C, which vibrates 261.63 times a second, is like seeing a color and knowing that it's a mustard yellow whose frequency in the visual spectrum is exactly 593 trillion times per second. And precisely pinpointing the parts of a chord is like seeing plaid and naming the frequency of every clashing hue. Scientists suspect that perfect pitch is a genetic trait that must be nurtured early on to bloom. People who start their musical training before the age of four are much more likely to have the gift than those who wait. But even among early achievers, perfect pitch is the exception to the rule.