Walt Disney's Carousel of Progress lyrics by Richard M. Sherman
1964 New York World's Fair
General Electric approached Walt Disney to develop a show for the company's pavilion at the 1964–1965 New York World's Fair. Disney leapt at the chance to rekindle his relationship with GE, who would fund the project and the new technology necessary to bring it to life. Reaching back to the Edison Square concept, he again pitched the idea of an electrical progress show to GE executives, who loved it.
During the planning phase, Disney's Imagineers perfected the Audio-Animatronics (AA) technology necessary to operate the "performers" in the show, using technologies similar to those in Walt Disney's Enchanted Tiki Room and Great Moments with Mr. Lincoln, another attraction designed by Disney for the 1964–1965 New York World's Fair. The Imagineers, led by Disney engineers Roger E. Broggie and Bob Gurr, also devised a "carousel theater", so that the audience could stay seated and ride around a stationary set of stages, instead of getting up and walking from stage to stage. This allowed the audience to remain comfortably in place during scene changes, avoiding time-consuming disruptions between acts.
Singing cowboy Rex Allen was tapped to voice Father, the host and narrator that replaced the original "Wilbur K. Watt" character. Allen later commented that he did not know exactly what he was getting into.
Walt Disney asked songwriters Richard M. Sherman and Robert B. Sherman to create a song to bridge the "acts" in the show. When he explained what the show was about, they decided to write a song based on Disney's enthusiasm, titled "There's a Great Big Beautiful Tomorrow". The brothers later said that they considered it Walt's "theme song," because he was so optimistic and excited about the future and technology itself.
The show opened at the Fair as Progressland, and was one of its most popular pavilions. Though more than 200 people entered and exited the attraction every four minutes, it was not uncommon to wait over an hour in line. For the Fair's 1965 season, a massive covered queue was constructed next to the pavilion on an empty lot to protect visitors from New York's hot summer sun.
At the end of the Carousel show, fairgoers were invited to walk up to the second floor of the pavilion and see the General Electric "Skydome Spectacular". The "Skydome Spectacular" projected images of nature and energy into the domed roof of the GE pavilion, similar to a planetarium. The show demonstrated the many ways that GE was harnessing electricity and the power of the sun for the benefit of its customers.  At the end of the Spectacular, in the first demonstration of controlled thermonuclear fusion to be witnessed by a large general audience, a magnetic field squeezed a plasma of deuterium gas for a few millionths of a second at a temperature of 20 million degrees Fahrenheit. There was a vivid flash and a loud report as atoms collided, creating free energy that was evidenced on instruments.  The temperature listed in the 1964 guidebook was 20 million degrees F; in the 1965 guide the temperature was up to 50 million degrees F.