"The Liberty Bell" is an American military march composed by famous bandmaster John Philip Sousa in 1893, and is considered one of his finest works. Many people associate it with the British comedy television show, Monty Python's Flying Circus, which played an excerpt over its opening titles. This tone is the "trio" of the march, and what makes this trio unique is the use of tubular bells, which symbolizes the Liberty Bell ringing in the distance. The bell part is usually started during the first breakstrain, but some bands start it right away at the first trio (as in this tone).
