Instrument families are groups of musical instruments that share similar characteristics and methods of sound production. The four main families are strings, woodwinds, brass, and percussion. String instruments, like the violin and cello, produce sound through vibrating strings. Woodwind instruments, such as the flute and clarinet, create sound by air passing through a reed or an opening. Brass instruments, including the trumpet and trombone, generate sound through the vibration of the player's lips in a mouthpiece. Percussion instruments, like the drum and xylophone, produce sound when struck, shaken, or scraped. Each family contributes unique tones and textures to music.