Gluck's manifesto

I have tried to restrict music to its true role of serving poetry through expression and by following the situation of the story, without interrupting the action or smothering it with useless, superfluous ornaments; and I believe that it should do this in the same way that telling colours affect a correct and well organized drawing, by a well matched contrast of light and shade, which animates the figures without altering their shapes.

-- Christoph Willibald Gluck, writing in the preface to the published score of Alceste