(CBS) — Today is the 40th anniversary of ‘Schoolhouse Rock,’ animated educational videos loved by millions today.

WBBM’s Keith Johnson spoke with the creative mind who helped make learning fun.

Bob Dorough was an ad musician making making a living in New York when an agency challenged him to put the multiplication tables to music.

“It took me two or three weeks to come up with ‘Three Is A Magic Number,’” said Dorough. “I wrote ‘Three is a Magic Number’ and they loved it and more or less said write more and write more.”

Dorough said his favorites are “Three is a Magic Number” and “Lolly, Lolly, Lolly Get Your Adverbs Here.”

Dorough is humbled and blown away by a new generation of Youtube fans. Not bad for a musician who thought “Three is a Magic Number” would end up as part of an instructional workbook.

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