Active in Paris, František Kupka developed a unique approach to abstraction influenced by his interests in music and spirituality. In this style of painting, known as Orphism, simultaneous color contrasts are equivalent to musical pitches. Kupka also painted abstract work as a means to visualize Theosophy—a synthesis of philosophy, religion, and science. The Cubist formal structure of this work, which brings together intersecting aspects of color, light, and mysticism, was inspired by the stained-glass windows of the Notre-Dame cathedrals in Paris and Chartres, France.