Sound energy is produced when an object vibrates. The sound vibrations cause waves of pressure that travel through a medium, such as air, water, wood or metal. Sound energy is a form of mechanical energy.
Multi-talented and prolific, Melvin Van Peebles (born 1932) paved the way for modern African American filmmakers and rap artists. Called "thegodfather of modern black cinema" because of his controversial 1970 film, Sweet Sweetback's Baadasssss Song, Van Peebles also wrote novels, wrote and produced Broadway musicals and TV shows, acted for film and television, and released several spoken-word albums in which he helped invent what later became known as rap music.