The valuable instrument was the work of the famous Pistoian organ builder Pietro Agati, who built it using part of an organ made by Cesare Romani da Cortona in the 16th century. Subsequently enlarged by the Agati (1824) and by the Tronci (1856), today it's a magnificent instrument with two thousand pipes of various materials - wood, tin, lead - with three keyboards and two pedalboards.
It's unique as it produces many 'special effects', such as rosignolo, grancassa, cappello cinese and piatto turco. It's played by Italian and international masters every year.
The organ continues to share Dominco Achilli's love for sacred music and for his village. Domenico, who died in 1845 without heirs, left all his possessions to the population of Gavinana. Among these is the sixteenth-century Palazzo Achilli, currently owned by the Municipality of San Marcello Piteglio, which houses the Information Point and the Naturalistic Archaeological Museum of the Pistoia Apennines, part of the Ecomuseum of the Pistoia Mountains.