English organum English English Organum organum Organum English English organum organum English English English English English English experiments organum http://en.wikipedia.org/wiki/Organum organum organum Organum English English English English English organum English organum English English English English organum English organum English organum English organum Organum experiments English English Organum experiments English Organum English Organum English English medieval chants English English organum English English experiments English English English English English English view article English experiments English English English English English plainchant organum http://en.wikipedia.org/wiki/Organum English http://en.wikipedia.org/wiki/Organum plainchant organum English