There are projects on which the artistic director of a record label straightaway asks himself a few questions. For example, when it comes to recording Beethoven's three 'greatest hit' sonatas, recorded a multitude of times by the leading pianists. However, a forte-pianist of the calibre of Alexei Lubimov already constitutes one good reason to implement the project, as does the choice of the facsimile of an Erard piano (1802, copy made by Christopher Clarke) of which the original was within Beethoven's reach. Above all, this recording presents a double interest: - the 'cross-disciplinary' thinking that preceded the recording, strictly speaking, and which was an integral part of the project. It brought together Christopher Clarke (builder), Thierry Maniguet and Jean-Claude Battault (curators), Alexei Lubimov, Catherine Kintzler (musicologist), Karoly Mostis (tuner), and the laboratory of the Cité de la Musique in Paris; - the possibility of sharing, in a digibook, this reflection on the instrument, its technique, the way to play it and the impact that all this has on the interpretation. At no moment does the result of this pluridisciplinary thinking restrain the performer's intentions - on the contrary! It is the source of new energy, both contemporary and highly respectful of the sources' intention.