The AM-1100 has achieved what many thought to be no longer physically possible; what petosa considers to be the art of perfection. The AM-1100 belongs to a class of its own, setting the standard by which all other accordions are compared. Uniquely and individually handcrafted from the highest quality materials through four generations of craftsmen, no accordion is as powerful in sound nor will endure the test of time like an AM-1100. The Cathedral model has an extended keyboard range with the addition of a fifth set of treble reeds. Inspired by the classical sounding Church Organ, the optional fifth set is a unique Quint reed. Alternatively, a third middle reed is optional to blend Musette and Concert tuning in a single instrument.