...It would eventually find no existing solution, so the engineers had to design and construct, on their own, one of the most complex and advanced audio systems ever built. The work paid off: today, as you walk through Disney World, the volume of the ambient music does not change. Ever. More than 15,000 speakers have been positioned using complex algorithms to ensure that the sound plays within a range of just a couple decibels throughout the entire park. It is quite a technical feat acoustically, electrically, and mathematically.
...The system he built can slowly change the style of the music across a distance without the visitor noticing. As a person walks from Tomorrowland to Fantasyland, for example, each of the hundreds of speakers slowly fades in different melodies at different frequencies so that at any point you can stop and enjoy a fully accurate piece of music, but by the time you walk 400 feet, the entire song has changed and no one has noticed.
