Complex sentence: It was built by Christian Müller and Jan van Logteren, from Amsterdam, between 1735 and 1738; upon completion it was the largest organ in the world with 60 voices and 32-feet pedal-towers.
Split into simpler sentences: It was built by Christian Müller and Jan van Logteren, from Amsterdam. They built it between 1735 and 1738; upon completion it was the largest organ in the world with 60 voices and 32-feet pedal-towers.