The music (notes) of those concerts comes from a manuscript kept in a private library in Assisi. The organ conceived as an orchestra, imitates the sound of the oboe, the flute, the human voice, the trumpets and hunting-horns with extraordinary mimetic effects. Before our examination, this manuscript, discovered by chance, showed no signs of having been studied and therefore this recording is an important contribution for defining Italian 18th-century organ-playing practices. Played on a Callido instrument in Corinaldo (really appreciated and often played by Pietro Morandi) it gives back the XVIIth organ majestic acoustic and lyric dimension true to the original. A listening.