Each vessel contains 12 discs recorded and donated by the French subsidiary of The Gramophone Company (ancestor of today's EMI). The firm's chief at the time, Alfred Clark, directed that the urns — which were interred in the basement of the Op_ra's home, the Palais Garnier, in a ceremony on Christmas Eve 1907 — should be opened after 100 years "in order to show men of that era the [current] state of 'talking machines' and the voices of the principal singers of our time."
In 1989 the containers were transferred from the Op_ra to the Bibliothque nationale for safekeeping.
The recordings feature such singers as Nellie Melba, Adelina Patti, Emma Calv_ and Enrico Caruso in such French and Italian repertoire of the time as Bizet, Gounod, Donizetti, Rossini and Verdi. (No complete list of the contents has appeared on the websites of the Bibliothque or the Op_ra.)
While the urns are now on view, the recordings are still inside: they were sealed within asbestos and will be removed in a special hazardous-materials facility next year. Once the discs are available, EMI will examine the contents and compile a CD for commercial release.
In addition, according to a statement from the Bibliothque, a similar ceremony will be organized "to preserve representative recordings of contemporary music" for the next 100 years.