[11] The November 30, 1928, issue of the Radio Service Bulletin therefore instructed its readers that, for the current WDAD-WLAC station list entry, to "strike-out call WDAD, as Dad's Auto Accessories (Inc.) is no longer joint licensee".

[12] On November 11, 1928, under the provisions of the Federal Radio Commission's General Order 40, WLAC moved to 1490 kHz, operating with 5,000 watts on a timesharing basis with the Waldrum Drug Co.'s WBAW.

In the early years of the station, WLAC provided local news, studio-orchestra musical features (accompanied by an in-studio pipe organ), farm reports, and some educational programming.

In 1941, with the implementation of the North American Regional Broadcasting Agreement (NARBA), WLAC moved to a "Clear Channel" assignment of 1510 kHz, and received permission to increase its power to 50,000 watts.

While WSM was a Class I-A station, using a non-directional antenna at all times, WLAC shared its clear channel assignment with KGA in Spokane, Washington.

Since WLAC and KGA were designated as co-equal Class I-B stations, both were required to use a directional antenna at night to mutually protect each other's signals.

Radio historians believe that the nightly "Rhythm and blues" WLAC shows, in part, laid the foundational audience for the rock and roll phenomenon that began in the late 1950s.

But he and the others reached large numbers of African-American listeners in places like the Mississippi Delta, the Carolina Lowcountry, Louisiana, Chicago, and Detroit, people whom practically no other radio stations were serving.

They did this mainly to attract advertisers who serviced the African-American community, such as hair-care products like Royal Crown Hair Pomade or chicken hatcheries, which packaged baby scrub roosters and other undesirable stock in large quantities for sale.

The deejays conducted the advertising sales on a "per inquiry", or commission, basis, meaning that the station did not rely on traditional ratings to gauge the programs' successes.

Performers of later years, such as Johnny Winter, and the Allman brothers, Duane and Gregg, have credited the station as being a valuable source of inspiration for their artistic development.

As a teenager, Robertson would stay up all night to hear blues from deejay John R. A strange irony about the phenomenon was unknown to most listeners of that time: all four disc jockeys were in fact middle-aged white men, not African-Americans, as their Southern, gravelly, drawling voices suggested.

Each deejay's program lasted from one to two hours per evening Mondays through Saturdays, occupying roughly (with adjustments over the years) the period between 8 p.m. and 2 a.m. Central Time.

In addition to this, most markets in WLAC's night-time coverage area now had black-oriented stations of their own, most of which attracted the demographic groups that formerly listened to Allen, Richbourg, and Nobles' shows as their only source for R&B and soul music (as it was known by the 1960s).

This made the Motown, Muscle Shoals, and Memphis sounds favored by the DJ trio (Grizzard died in 1971) seem passé, and the hosts' audience, unsurprisingly, began to age, something that advertisers, focusing by then on youth rather ethnicity, almost always react adversely against.

To replace the retiring jocks, the station recruited young Spider Harrison, a native New Yorker who at the time was an afternoon urban air personality and program director at WTLC-FM in Indianapolis.

Harrison steered the nighttime format into a blend of soul and rock, in an attempt to target an entire new generation of young night-time listeners throughout the country.

However, WLAC struggled for most of the 1970s to obtain Arbitron ratings improvements from local listeners, despite frequent promotional events staged throughout the Nashville area.

The new schedule, (as reported in The Nashville Tennessean newspaper's "Sunday Showcase") included news coverage weekdays from 6 to 9:30 a.m., Noon to 1 p.m., and 4:30 to 7 p.m., when the regular nighttime "ethnic music" programming began.

Also, former WSM, WSMV and WKRN-TV personality Teddy Bart launched his critically acclaimed "Roundtable" interview program on WLAC's morning schedule in 1985.

The nighttime line-up included paid broadcasts of many evangelical, fundamentalist, and Pentecostal preachers, seeking donations for their ministries, with the news/talk format resuming at daybreak (after the Hoss Allen show).

For many years, WLAC was the Nashville home of the University of Tennessee Volunteers, bringing Vols football and men's basketball to much of North America at night.