The Leslie Speaker is a type of electronic musical device used primarily with electric organs and synthesizers. It produces a distinctive sound by using a rotating speaker system, which creates a rich, swirling effect. This unique sound has made it popular in various music genres, especially in jazz, rock, and gospel. Invented in the 1930s by Don Leslie, the Leslie Speaker has become an iconic part of music history. It typically features two speakers: one for high frequencies and another for low frequencies, each rotating at different speeds. This design enhances the audio experience, making it a favorite among musicians and audio engineers.