Do you want to hear the world's largest pipe organ?
This video was made at Wanamaker's (Macy's) Department Store in Philadelphia on October 30, 2010. There were 650 people singing the Hallelujah Chorus (from Handel's Messiah) accompanied by Mr. Peter Conte at the organ console. This event was a part of the Philadelphia Opera's "Random Act of Culture" program.
The organ was built by the Murray Harris Organ Company of Los Angeles for a World's Fair, held in St. Louis, Missouri, in 1915 (I think it was). At the time, Mr. Harris was the most famous organ builder in the United States, and he had a personal dream of building the "world's largest pipe organ," so he did it for the World's Fair. After the fair, the organ was moved into this huge department store, where it is sometimes played during store hours to entertain shoppers. There are also concerts given there on certain evenings. I think the pipes are hidden in rooms on various floors and in the ceiling.
Guess what? The organ in the Saint Mary's College Chapel (first built in 1859) was completely rebuilt and "modernized" by Murray Harris in 1901. Thus, the SMC organ has many sets of pipes built by the Harris company, and many of its sounds match those of the organ on this video.
This organ is probably no longer the world's largest pipe organ. The title belongs to the organ in a famous Cathedral in Germany.