It in no way prepares for that admirable chorus at the beginning--unequaled of its kind--which Orpheus's broken hearted cry of "Eurydice! Eurydice!" makes so pathetic.
The first act of _Orfeo_ ends in a tumultuous effect of the stringed instruments which was evidently intended to indicate a change of scene and the appearance of the stage settings of the infernal regions.

This passage does not appear in the French _Orphee_ and it is lacking in the engraved score, where it is replaced by a bravura aria of doubtful taste, accompanied by a single quartet.

Whether the stage managers wanted an entr'acte or the tenor, Legros, demanded an effective aria, or for both these reasons, a reading of the manuscript indicates how absolutely the author's meaning was changed.

There is no doubt that except for some such reason he would have changed this aria and put it in harmony with the rest of the work.
For a long time this aria was attributed to Bertoni, the composer, and Gluck was accused of plagiarizing it.

As a matter of fact, and to the contrary, this aria came from an older Italian opera of Gluck's.