A string quartet is a musical ensemble made up of four string instruments: two violins, a viola, and a cello. This combination creates a rich and harmonious sound, allowing for a wide range of musical expression. String quartets often perform classical music, but they can also explore various genres, making them versatile and popular among musicians and audiences alike. The structure of a string quartet typically includes several movements, each with its own mood and tempo. Famous composers like Ludwig van Beethoven and Wolfgang Amadeus Mozart have written iconic string quartets that are still celebrated today. These works are often performed in concert halls, bringing together music lovers to enjoy the beauty of live string performances.