* Strings: Instruments that produce sound by vibrating strings, such as violins, cellos, and guitars.
* Woodwinds: Instruments that produce sound by blowing air across a reed, such as clarinets, saxophones, and flutes.
* Brass: Instruments that produce sound by vibrating their metal mouthpieces, such as trumpets, trombones, and tubas.
* Percussion: Instruments that produce sound by being struck, such as drums, cymbals, and xylophones.