In The 21st Century Voice: Contemporary and Traditional Extra-Normal Voice, Michael Edward Edgerton considers contemporary vocal techniques within an advanced acoustic and anatomical framework. Throughout, he proposes new directions for vocal exploration. Much more than a treatise on twentieth-century vocal science and study, The 21st Century Voice explores experimental methods of sound production, offering a systematic series of approaches and methods for assessing, engaging, and, in some instances, overcoming the assumed limits of vocal singing.