Francis Hueffer and Donald Francis Tovey, 1911 Encyclopædia Britannica, Volume 12… (1911)
“ Indeed only a great musician could so reform opera as to give it scope for dramatic power at all. Where Gluck differs from the greatest musicians is in his absolute dependence on literature for his inspiration. Where his librettist failed him (as in his last complete work, Écho et Narcisse) , he could hardly write tolerably good music; and, even in the finest works of his French period, the less emotional situations are sometimes set to music which has little interest except as a document in the history of the art. ”
