In 1922... WBAP began broadcasting May 2, 1922.
The station shared time with Dallas stations WFAA and WRR. It was the first station in the United States to have an audible logo signal similar to the NBC chimes, the WBAP cowbell. According to Herbert Hoover, the station's call letters stood for "We Bring A Program".
On May 15, 1923, the Federal Radio Commission expanded the broadcast band, and WBAP and WFAA moved to 630 kHz. Another expansion moved WBAP to 600 kHz effective April 15, 1927, and this frequency was shared with WOAI in San Antonio. On November 11, 1928, WBAP moved to 800 kHz, and on June 1, 1929, WFAA also moved to 800 kHz, sharing time (and NBC Red network affiliation) with WBAP.
Station owner Amon G. Carter was unhappy with having to share time on 800 kHz with WFAA. In May 1938, Carter Publishing purchased KGKO Wichita Falls (570 kHz) and moved it to Fort Worth as an affiliate of the NBC Blue network (which became ABC), and more importantly as a second frequency to be used when 800 kHz was not available. On March 29, 1941, as a consequence of the Treaty of Havana, WBAP and WFAA moved one last time, to 820 kHz.
Carter eventually sold half of KGKO to A.H. Belo, owners of WFAA, and on April 27, 1947, KGKO was replaced by a second shared frequency between WBAP and WFAA.
The dual frequency sharing arrangement between WBAP and WFAA continued through the 1950s and 1960s, with the stations switching frequencies several times a day. When WBAP changed frequencies, it signaled the change with a cowbell, which became widely associated with the station.
Even though the stations swapped frequencies several times each day, the network affiliations remained constant: NBC network programming stayed on 820 kHz and ABC network programming stayed on 570 kHz. This frequently proved confusing for announcers and listeners alike.
On May 1, 1970, the unique dual split-frequency lives of WBAP and WFAA ended when WBAP paid $3.5 million to WFAA in exchange for sole occupancy of 820 kHz (and the NBC affiliation).
WFAA took on 570 kHz (and the ABC affiliation) full-time. Once the frequency-sharing with WFAA ended in 1970, both stations were free to program musical formats, and WBAP began programming country music.
It also gained the added benefit of 820's clear-channel signal; previously WFAA controlled it during these prime nighttime hours. After a series of network affiliation changes in the late 1970s among WBAP, KRLD and WFAA, WBAP switched affiliations to ABC.
In 1928...
KPQ-AM, Wenatchee, Washington, began broadcasting.
In 1932...the first Radio show featuring comedian Jack Benny debuted on the NBC Blue Network. Here's a video clip from 1942.
In 1960...WLS 890 AM, Chicago, Illinois, switched its format from Country to Top 40. The first record played was "Alley-Oop" by the Hollywood Argyles.
In 1963...DJ Dick Biondi did his last show on WLS-AM, Chicago. Here's some audio from a 1962 show: