24 Préludes, Op. 28, C. 166-189 - Chopin: 24 Préludes, Op. 28, C. 166-189: No. 15 Sostenuto in D-Flat Major, C. 180 "Raindrop" (24首前奏曲，作品28 - 降D大调第15首（雨滴）) (Live)