Percussion instruments are the heartbeat of music. They create rhythm, define tempo, and bring energy and structure to musical compositions across cultures. From the deep resonance of a mridangam to the sharp crack of a snare drum, percussion instruments come in countless forms and are found in nearly every musical tradition in the world. This chapter explores the diverse world of percussion—its classifications, cultural significance, playing techniques, and acoustic principles. It delves into both ancient frameworks, such as Bharata Muni’s Natya Shastra in Indian classical music, and modern systems used globally to categorize membranophones, idiophones, and more. More than just instruments of rhythm, percussion tools are powerful vessels of tradition, communication, and expression. Whether used in rituals, orchestras, or experimental music, their universal presence reveals a shared human instinct to connect through sound. This chapter invites readers to experience percussion not only as instruments but as storytellers that speak through vibration and time.