Art rock emphasizes Romantic and autonomous traditions, in distinction to the aesthetic of the everyday and the disposable embodied by art pop. Larry Starr and Christopher Waterman's "American Popular Music" defines art rock as a "form of rock music that blended elements of rock and European classical music", citing the English rock bands King Crimson, Emerson, Lake & Palmer, and Pink Floyd as examples. Common characteristics include album-oriented music divided into compositions rather than songs, with usually complicated and long instrumental sections, symphonic orchestration. Its music was traditionally used within the context of concept records, and its lyrical themes tended to be "imaginative" and politically oriented.