The double bass is the largest string instrument in the orchestra, known for its deep, rich sound. It has four strings, which are typically tuned to E, A, D, and G, and is played with a bow or by plucking the strings. Musicians often use the double bass in various music genres, including classical, jazz, and folk. In orchestras, the double bass provides the foundation of the harmony, supporting the other instruments. Famous composers like Johann Sebastian Bach and Wolfgang Amadeus Mozart wrote music that features the double bass, showcasing its versatility and importance in ensemble performances.