Gravitational Waves is a dating story. The pianist Bruno Ruder and the saxophonist Rémi Dumoulin know each other for a long time and have very early maintained more than friendly relations (Bruno Ruder calls Rémi Dumoulin his brother). When the idea of starting a group together germinated, the choice of the drummer was quickly stopped, so great was the desire to rework with the legendary Billy Hart . There is also little suspense about the rest of the cast: Aymeric Avice (Radiation 10, Jean Louis, Circum Grand Orchestra) and Guido Zorn (Rockingchair, Pierre Durand Roots 4tet), two musicians among their favorites. Ruder and Dumoulin share voluntarily very open compositions (sinuous and fragile for the pianist, more direct for the saxophonist). The decision is to leave the maximum space to the American drummer so that it colors the score as it sees fit.