How was NBC's chime created?

The NBC chimes were created as a practical solution to a radio problem in the early days of broadcasting. Originally, when transitioning between segments like news and radio dramas, there were issues with static noise caused by physically changing patch cords. The chimes were used to cover this noise and make the transitions smoother. Initially, the chime sequence was more complex, consisting of seven notes, but it was eventually simplified to the three-note sequence we recognize today. Interestingly, the chimes also served to notify affiliate stations of important news, such as the "fourth chime" used during D-Day to alert stations of the event 1.