Complex sentence: Kupka's 1909 painting "Piano Keyboard/Lake" marked a break in his representational style; his work became increasingly abstract around 1910--11, reflecting his theories of motion, color, and the relationship between music and painting (orphism).
Split into simpler sentences: Kupka's 1909 painting "Piano Keyboard/Lake" marked a break in his representational style. His work became increasingly abstract around 1910--11, reflecting his theories of motion, color, and the relationship between music and painting (orphism).