In Western culture, from ancient Greece until the High Renaissance, music was typically considered to be a higher art form than the purely "mechanical" work of visual art because of its connections to abstract, mathematically driven principles of harmony and meter, which were believed to connect to a higher, "divine" ordering in the universe. Such ideas were applied to art beginning in the 15th century. For example, Leon Battista Alberti's architectural designs made explicit reference to musical harmony and employed ratios that he thought would produce consonances. This type of practice became widespread in Renaissance architecture and soon found a place in investigations of linear perspective in drawing and painting, such as in the work of Leonardo da Vinci. Music was essential to early forays into abstraction at the beginning of the 20th century, as it served as an ideal starting point for emotive, non-representational compositions such as those of Wassily Kandinsky, Paul Klee, and Francis Picabia, all of whom were part of artistic and intellectual communities that included musicians. A radical rejection or parody of traditional forms of music was central to Dada, Nouveau Réalisme, and Fluxus. Most recently, several contemporary artists, such as Janet Cardiff and Christian Marclay, have made recording and broadcasting music a primary part of their work.