[...] Gluck’s chief claim to distinction is that he was an opera reformer. The author credits Count Durazzo, intendant of the Vienna theatres, as the instigator of opera reform. Durazzo gave Gluck his appointment as Kapellmeister and also wrote librettos which Gluck set to music. Other writers have pointed to Metastasio as the originator of the reforms: and there were others, among them Noverre, who wanted to reform the ballet. Both were pamphleteers. It was with his eye on the reforms suggested by Noverre that Gluck wrote his ballet of Don Juan.

Opera abuses had grown with the development of opera since its inception in Italy. For many years the Italian composer of operas had been a mere hack supplying music for the technique and idiosyncrasies of soloists, who were male sopranos with unnatural but powerful voices. Calzabigi the librettist, himself an opera reformer, condemned what he said was a crime against children, and gradually the practice which produced such voices ceased and the castrati disappeared from the Italian stage.

Gluck swept aside vocal display and spoken dialogue and used the legendary myths of Greece in place of historical subject, worn threadbare by repetition. With subjects more sympathetic to musical treatment, he strove to express rather than to decorate. He had a dual instinct, dramatic and orchestral, and employed both in cultivating continuity of writing. Hitherto opera had been little more than an elementary musical play, moving by stops and starts, but Gluck gave it the dramatic continuity of the spoken drama.[...]