 Since the beginning of the 21st century a project has been under way to release scholarly and reliable scores of Offenbach's operas, under the editorship of Keck.The first to be published, in 2002, was the 1858 version of "Orphée aux enfers".The Offenbach Edition Keck has subsequently published the 1874 score, and another drawing on both the 1858 and 1874 versions.