A new version of the opera, conducted by Spontini, was performed in Paris on Wednesday, 22 October 1817. A manuscript score in four volumes, beautifully written in several hands, has been preserved. This rendition of Salieri’s score was extremely successful, and it made such an impression, among others, on the young Berlioz, that it led him to dedicate himself music. It is for this new version that Spontini composed his Bacchanals, a powerful danced chorus mentioned by all the chronicles of the period. The present paper sheds new light on the score of the revised version of Les Danaïdes. It offers a description of the musical pieces, integrating (in square brackets) the indications taken from the corresponding libretto. It thus provides a first series of observations on the changes made between the new and the original versions.