What are the four types of musical instruments and what are the physical behind

The four types of musical instruments are percussion, woodwind, brass, and strings.

Explanation:

Percussion instruments include drums, triangle, cymbals, and xylophones. There are more instruments than what i've mentioned though. Percussion instruments often produce the beat of songs.

Woodwind instruments include clarinets, oboe, flute, and saxophone. Woodwind instruments often produce the harmony of songs and, occasionally, the melody.

Brass instruments include trumpet, trombone, french horn, and tuba. Brass instruments often produce the harmony of songs, the trumpet produces the melody a lot though.

String instruments include guitars, violins, cello, bass, ukulele, and banjo. String instruments produce both the harmony and the melody. These instruments often produce really beautiful music, in my opinion.