From busking to the stage, Catherine and Gregory, two charismatic young classical singers, live out their passion in an unconventional way. This soprano and baritone have invented a new form of "performance": beneath a bridge spanning the Seine or in the gardens of the Palais Royal, they practice their art with spontaneity and talent and a tape-recorder for their only support. Initiators of the association “Voix-Si, Voix-La, Opéra Sans Frontières” they try to loosen the constraints of this closed milieu, for both spectators and performers. Before a fascinated and receptive audience, they show that opera doesn’t always require a huge stage to create emotion. The film follows them from breakfast-time scales to advice from their singing teacher and on to a hall with exceptional acoustics which they were able to rent for an evening.