The National Barn Dance! It had one hell of a run:

National Barn Dance, broadcast by WLS-AM in Chicago, Illinois starting in 1924, was one of the first American country music radio programs and a direct precursor of the Grand Ole Opry.[1]

It also set the stage for other similar programs, in part because the clear-channel signal of WLS could be received throughout most of the Midwest and even beyond in the late evening and nighttime hours, making much of the United States (and Canada) a potential audience. The program was well received and thus widely imitated. National Barn Dance ended its broadcast in 1968.

Alka-Seltzer also sponsored Lum & Abner; I'd be curious to know if they decided to go for a rural approach.You'd think it's at odds with the people in the ads, but those could be farm folk dressed up for Sunday dinner.