The old engraved scores of Gluck's works reproduced his manuscripts faithfully enough, but they bore evidence of carelessness and amazing inaccuracy.

They are mere sketches instead of complete scores.

Many details are vague and vagueness is not permissible in a serious edition.

It follows that the different editions of Gluck's works published in the Nineteenth Century, however sumptuous or careful they may be, are worthless.

The Pelletan edition alone can be consulted with confidence, because we were the only ones to have all extant and authentic documents in the library at the Opera to set us right.