Rameau's ""Io"" has only survived posthumously, namely in the form of a copy of the score and the orchestral parts, both of which were produced in Rameau's successor generation from the now lost autograph. The edition of this Acte de Ballet prepared by the Opera omnia Rameau is therefore a first edition based on non-original sources, which are also fragmentary.

In order to make the piece performable, the OOR decided to complete the ending using sequences from the early version of the opera ""Platée"" and to precede it with a symphony from the same piece as an overture, as the score simply begins with a recitative. The introduction to the volume examines in detail the evidence on questions of dating as well as various hypotheses about performance possibilities and librettists. The dating is central to the approach of completion, as there is much to suggest that ""Io"" must have been composed between 1740 and 1745, the creative period from which the early version of ""Platée"" also originates.

- Excavation of a small treasure from Rameau's pen

- Completion with original music by Rameau

- First edition with an informative text section on the probable context of the work’s creation

- Jean-Philippe Rameau. Opera Omnia (OOR) V/1

- Also available for sale vocal score BA8869-90