Which instrument is NOT classified as a percussion instrument?

The flute is classified as a woodwind instrument rather than a percussion instrument. Percussion instruments produce sound when struck, shaken, or scraped, and they rely on the vibration of the instrument itself to create sound. In contrast, the flute produces sound through the vibration of air, which is created by blowing across an opening.

Drums, xylophones, and cymbals are all percussion instruments. Drums generate sound by being struck with sticks or hands, while the xylophone consists of wooden bars that are struck with mallets. Cymbals create sound by being crashed together or struck with sticks. Therefore, the flute's method of sound production clearly distinguishes it from the percussion family.