The "Beethoven Quartet" typically refers to a group of string quartets composed by Ludwig van Beethoven, a prominent German composer of the late 18th and early 19th centuries. His quartets are significant in the classical music repertoire, showcasing his innovative approach to harmony, structure, and emotional depth. Notable works include the Rasumovsky quartets, which are known for their complexity and expressiveness. Beethoven's quartets evolved throughout his career, reflecting his personal struggles and artistic growth. The late quartets, particularly String Quartet No. 14 in C-sharp minor, Op. 131, are celebrated for their profound introspection and intricate counterpoint. These works have influenced countless composers and continue to be performed worldwide.