type of serious musical theatre, first advanced by Richard Wagner in his book Oper und Drama (1850-51; "Opera and Drama"), that was originally referred to as simply "drama." (Wagner himself never used the term music drama, which was later used by his successors and by critics and scholars.) This new type of work was intended as a return to the Greek drama as Wagner understood it-the public expression of national human aspirations in symbolic form by enacting racial myths and using music for the full expression of the dramatic action. Wagner's emphasis on opera as drama merely resumed and developed the ideas of Claudio Monteverdi and Christoph Gluck. He envisaged the disappearance of the old type of opera, with its libretto provided by a hack versifier, as an opportunity for the composer to make a "set piece" opera out of purely musical forms separated by a recitative.