The RCA Educational Hour

This program launched in October of 1928 on the the NBC Blue Network. It's host was Dr. Walter Johannes Damrosch. It was not a math class or a series of history lectures. It was a music appreciation class and was also called "The Music Appreciation Hour" and The Damrosch Hour. I took one of those classes in high school. The professor was a nice well-intentioned man, but I didn't appreciate it at the time.Franklin Dunham at NBC arranged all the particulars. He had been in charge of education at Aeolian Hall in new York. He arranged a few recital broadcasts at WJZ, and was hired as an advisor to their musical department. When NBC was formed he scored a gig there on an advisory committee for musical programs.
Hundreds of schools participated in this program. At least 28 stations syndicated it across the country. The program sent out a 70-page teachers manual free to educators. (I want a copy) NBC ran the show during the school day to facilitate it's use in the classroom it ran Fridays at 11am from 1928 to 1938 then was moved up to 2pm which strangely the program survived. Its first test broadcasts aired in 1923 on WEAF-AM and only became a regular series in 1928. The show was divided for children of different age levels making really two pairs of half-hours programs broadcast on alternate weeks: Series A was intended for use in grades three and four; series B in grades five and six; series C in grades seven, eight, and nine; and series D in high-school and up. More here.

Ernest LaPrade, reporting on the program at the Institute for Education by Radio at
Columbus, Ohio, in 1930 wrote:

"...Certain educators have proposed that radio should not attempt to teach anything that can be taught in the classroom. ... I should say that, at any rate, radio should not attempt to teach anything that can be taught better in the classroom. Appreciation of symphonic music seems to be one thing that can be taught better by radio than in any classroom, because it is impossible to introduce a symphony orchestra into a classroom."

Damrosch was 66 years old when the program started and 80 when he finally retired. He was the Prussian son of conductor Leopold Damrosch. He emigrated to the United States in 1872 and became the second conductor of the Metropolitan music house, and spend another 40 years conducting the New York Symphony Orchestra. Damrosch was the National Broadcasting Company's music director under David Sarnoff, and from 1928 to 1942. The program stopped when Damrosch retired in 1942. He died 8 years later. More here.