The document classifies musical instruments into four categories: string, woodwind, brass, and percussion, detailing the characteristics and examples of each. String instruments like the violin and cello play a central role in orchestras, while woodwinds, such as the flute and clarinet, produce sound through blowing. Brass instruments like the trumpet and tuba rely on brass construction and blowing for sound, while percussion instruments, including the snare drum and xylophone, are played by striking or shaking.