However, in the first decades of the 20th century, several composers such as Debussy, Schoenberg, Berg, Hindemith, Stravinsky, Prokofiev and Bartók started experimenting with ideas that were to have far-reaching consequences for the way music is written and, in some cases, performed. Some of these innovations include a more frequent use of modality, the exploration of non-western scales, the development of atonality and neotonality, the wider acceptance of dissonances, the invention of the twelve-tone technique of composition and the use of polyrhythms and complex time signatures.