Complex sentence: At his first engagement, on 15 May at Stafford House, the audience included Queen Victoria and Prince Albert; the Prince, who was himself a talented musician, moved close to the keyboard to view Chopin's technique.
Split into simpler sentences: At his first engagement, on 15 May at Stafford House, the audience included Queen Victoria and Prince Albert. The Prince, who was himself a talented musician, moved close to the keyboard to view Chopin's technique.