Beethoven's "Rasumovsky" quartets, dedicated to the Russian ambassador to Austria, incorporate beautiful Russian melodies, marking the composer's first earnest use of folk music in his work. The "Harp" Quartet, nicknamed for its evocative use of plucked strings, is one of Beethoven's most symphonic chamber works and its serene second movement is one of his loveliest melodies. Opus 95 is full of harmonic daring and tense contrasts, presaging Beethoven's later style and proudly dubbed "Quartetto Serioso" by the composer himself. The Emerson Quartet, unparalleled for its tonal palette and perfect sonic balance, gives performances for the ages in this generous set.