Harlem Quartet @ Sugar Hill: Beethoven, Wynton Marsalis, William Bolcom, William Grant Still + more. In many ways, Ludwig van Beethoven’s turbulent and fiercely concentrated Op. 95 “Serioso” Quartet points toward the restless individuality that defines so much American music today. Its sharp contrasts, rhythmic urgency, and emotional directness resonate across genres and generations—from the jazz-infused classical language of William Bolcom, to the stylistic fluency and improvisatory spirit of Wynton Marsalis, the lyrical originality of William Grant Still, and the virtuosic cross-cultural voice of Aldo López-Gavilán.