Originally a grand instrument with a traditional disposition, the organ of Santa María Zaachila was extensively modified between 1910 and 1925 to produce a more romantic sound. The trumpet stops were canceled; the row of wooden rings marks where the horizontal trumpets (clarín) had been positioned. A pedalboard was installed, which required an extension on the back of the organ for the 16´ rank of stopped wooden pipes and an additional wind chest to feed them. The pipes were cut to raise the pitch to 440 Hz. The porcelain stop knobs are unusual, and in fact, some of them are too close to those next to them to pull out at the same time.