At the peak of the British Invasion, American folk music was working its way into youth culture. Bands shifted from traditional rock 'n' roll subject matter toward social issues & drugs. Guitarists added fuzz to the British sound, creating dreamy, spacious textures. The influences of Free Jazz and Eastern instrumentation were felt as well. Hear Roger McGuinn's Indian-influenced opening guitar in The Byrds' "Eight Miles High," or George Harrison's sitar.