Resultant Tone

Divided into two categories, difference tone and summation tone, a resultant tone is a third and/or fourth note that are produced when two loud notes are played simultaneously. The difference tone is a lower note whose pitch is the difference between the frequencies of the two notes. This effect is most noticeable when clarinets are playing in thirds. The fourth note, or summation tone, is a higher note, which is the result of the sum of the frequencies of the two notes.