Here's what the Atlanta radio dial looked like in 1966 per the AJC:
WPLO 590 Country (WPLO flipped from RnR to Country--really Town & Country, see below--in the early 60s.)
WSB 750 Popular (NBC) (Popular was the softer side of Top 40, approaching but not necessarily as soft as MOR.)
WQXI 790 Top 40
WERD 860 R&B/Jazz
WGST 920 Popular (ABC) (The AJC still listed the four network affiliates back then.)
WIIN 970 Popular
WGUN 1010 Country (Mutual)
WBIE 1080 Standards (CBS) (Standards was the AJC term for BM/EZ.)
WGKA 1190 Classical (and they stuck with classical on AM until the 90s, bless their hearts!)
WFOM 1230 Top 40
WTJH 1260 Country
WOMN 1310 Popular
WIGO 1340 R&B (WAKE threw in the towel on Top 40 due to their weak Class C signal and the expanding suburbs.)
WAOK 1380 R&B (The AJC would later call the R&B format "soul", then "black", before the term "urban" became commonplace.)
WAVO 1430 Religious (Not sure if the frequency is a typo.)
WYZE 1480 Town & Country (Town & Country was a modern spin on the country format--no corn-pone, easy on bluegrass etc., and more sophisticated imaging. WPLO pioneered it in ATL.)
WYNX 1550 Town & Country
WAIA 1570 Country (became Top 40 WBAD in 1967)
WABE 90.1 Educational
WGKA 92.9 Classical
WKXI 94.1 Finance (I think WKXI was also playing BM/EZ--or standards to use the AJC's term--between stock reports.)
WAVO 94.9 Religious (AJC had 94.9 as WAVO and not WAVQ, but 94.1 was still WKXI.)
WKLS 96.1 Standards (Stereo)
WSB 98.5 Popular (Stereo) (Later flipped to BM/EZ; here's a commercial
https://www.youtube.com/watch?v=arnCg-F21NA&t=2942s .)
WLTA 99.7 Standards (Stereo)
WBIE 101.5 Standards (Would flip to country in 1968.)
WPLO 103.3 Popular (Would soon become ATL's first AOR station after Plough leased it out to Ga. State for the students to program, in the days before WRAS Album 88.)