The Civil War, and the period following it, saw a general flowering of American art, literature and music. Amateur musical ensembles of this era can be seen as the birth of American popular music. Music author David Ewen describes these early amateur bands as combining "the depth and drama of the classics with undemanding technique, eschewing complexity in favor of direct expression. If it was vocal music, the words would be in English, despite the snobs who declared English an unsingable language. In a way, it was part of the entire awakening of America that happened after the Civil War, a time in which American painters, writers, and 'serious' composers addressed specifically American themes." During this period the roots of blues, gospel, jazz, and country music took shape; in the 20th century, these became the core of American popular music, which further evolved into the styles like rhythm and blues, rock and roll, and hip hop music.