Tone variation refers to the changes in pitch, volume, and quality of voice that convey different emotions or meanings in spoken language. It can indicate excitement, sadness, anger, or calmness, helping listeners understand the speaker's intent beyond just the words used. In music, tone variation is essential for creating dynamics and expressing feelings. Musicians use techniques like vibrato and crescendo to alter the tone of their instruments or voices, enhancing the emotional impact of a piece. This variation helps to engage the audience and adds depth to the performance.