What is an overtone in music and how does it contribute to the overall sound of a musical piece?

An overtone in music is a higher frequency sound that is produced along with the main tone when a musical instrument is played or a voice sings. These overtones give richness and complexity to the sound, creating a full and harmonious quality to the music. They contribute to the overall sound of a musical piece by adding depth and color, enhancing the timbre and texture of the music.