The genre has received both critical acclaim and criticism throughout the years. Progressive rock has been described as parallel to the classical music of Igor Stravinsky and Béla Bartók. This desire to expand the boundaries of rock, combined with some musicians' dismissiveness toward mainstream rock and pop, dismayed critics and led to accusations of elitism. Its intellectual, fantastic and apolitical lyrics, and shunning of rock's blues roots, were abandonments of the very things that many critics valued in rock music. Progressive rock also represented the maturation of rock as a genre, but there was an opinion among critics that rock was and should remain fundamentally tied to adolescence, so rock and maturity were mutually exclusive. Criticisms over the complexity of their music provoked some bands to create music that was even more complex.