A Brief History of the Original Series
The series of animated cartoon shorts - 41 segments in all - used appealingly goofy characters, catchy tunes and repetition (airing as often as seven times each weekend) to teach Fruity Pebbles consumers about multiplication tables, the parts of speech, American History, Science and computer mechanics.
Schoolhouse Rock's genesis took place in 1971 when David McCall, chairman of big-time New York ad agency McCaffrey & McCall, noticed that his son could song every Beatles and Stones lyric ever recorded but couldn't handle simple multiplication tables.
His solution was simple: link math with contemporary music and the kids will breeze through school on a song.
To implement his idea, McCall turned to his agency's creative staff, who passed suggested they hire Bob Dorough, a Texas jazz musician with a knack for infectious grooves. The composer /pianist accepted his mission with great enthusiasm, plowing through his daughter's arithmetic books and plunking our notes until he'd created the soothing ballad "Three is a Magic Number. "
And that was the beginning of School House Rock.
The above is from the website: http://www.school-house-rock.com/history.htm

