This project is a collaboration between the two organists Margherita Gianola and Silvio Celeghin with Francesco Fanna, conductor and director at the Istituto Italiano Antonio Vivaldi of the Fondazione Giorgio Cini in Venice, in which large part of Vivaldi’s manuscripts and scores are archived. The CD is a collection of Concertos where the organ is the absolute protagonist as soloist and in an interesting interaction with string instruments. The title of the release is inspired by the two organs of the XVIII century in the Basilica dei Frari in Venice which are exceptionally appropriate for playing Vivaldi’s music. The Callido (1795) is very versatile and enhances the whole sound, while the Piaggia (1732), the only organ in Venice made while Vivaldi was still alive, is elegant, light and full of verve.