NBC chime machine

The NBC chimes are a sequence of three tones played on National Broadcasting Company (NBC) broadcasts. Originally developed in 1927 as seven notes, they were standardized to the current three note version by the early 1930s, and possibly as early as 1929. The chimes were originally employed as an audible programming cue, used to alert network control engineers and the announcers at NBC's radio network affiliates. They soon became associated with NBC programming in general, and are an early example of an "interval signal" used to help establish a broadcaster's identity with its audience.

In 1950 the NBC chimes became the first "purely audio" service mark granted by the U.S. Patent and Trademark Office. Nearly ninety years after their introduction, they continue to be used as an audio signature by the NBC TV network and its affiliates, and also on the NBC Sports Radio network and at the opening of the hourly NBC News Radio broadcasts.

The NBC chimes sound mark is currently assigned to NBC Universal Media, LLC. Its official description, as recorded by its registration at the U.S. Patent and Trademark Office, is:

"The mark comprises a sequence of chime-like musical notes which are in the key of C and sound the notes G, E, C, the 'G' being the one just below middle C, the 'E' the one just above middle C, and the 'C' being middle C, thereby to identify applicant's broadcasting service."

While general information about the origin of the NBC chimes is well documented, precise details about the earliest developments are not as clear, and in some cases researchers have come to differing conclusions. It is particularly difficult to establish exactly when the initial, longer, versions were pared down to the final three-tone sequence.

A commonly suggested explanation for the chimes' "G-E-C" sequence is that it comes from the initials of the General Electric Company (GE). In 1987, Robert C. Wright, the president and C.E.O. of NBC, testified before the U.S. Congress that "Not everyone knows that GE was one of the original founders of RCA, NBC's former parent, and that the notes of the famous NBC chimes are G-E-C, standing for the General Electric Company." References to this purported link date back to at least 1945. However, this was over a decade after the NBC chimes were adopted, and NBC's own early historical reviews make no mention of this supposed origin.

...
Wikipedia