The other day, I heard The New Seekers ‘I’d Like To Teach The World To Sing’ for the first time in many years, and recalled Coke using the melody with altered lyrics for a 1971 ad program.
Then I pondered-what was the first time a pop tune was used in this manner?
Over to you, triviaholics! 
My money’s on Anticipation, for a ketchup commercial. I don’t have a cite, and I don’t remember when it first aired, just that I was surprised to hear a “real” song, and not a jingle.
I was surprised again when Chevy started using Like a Rock, but that might be way more recent.
I was gonna say the Alka Seltzer song, but I think that was a case where the commercial came first, then the recording.
this article is about that very same thing. Salesnoise: Music and Advertising
According to it,
This appears to be the first use of a previously existing song of popular culture that was then used in advertising.
“I’d Like to Teach the World To Sing” and “No Matter What Shape (your stomach’s in)” we’re taken from the ads.
Also, the Carpenter’s “We’ve Only Just Begun” was adapted from a bank commercial in 1970.
Mapcase’s Second Law: Everything is older than you think it is.
What about political advertising? I would think that political candidates, especially in the U.S., used popular songs in their campaigns.
Well, I can’t beat the 1908 cite; but…
Buckle Down Winsocki was used in a PSA to inform people about the advantages of seat belts. (Buckle up for safety, buckle up!)
Suzuki riffed on Get Happy. (Forget your troubles, c’mon Suzuki…)
Janice Joplin’s Let The Good Times Roll featured in Kawasaki’s ads. (Kawasaki lets the good times roll…)
Carly released her ‘Anticipation’ album in 1971 such that the Hunt’s commercial was produced later.
Are you alleging that these pop songs came from ad tunes, Mr. Blue Sky? 
Well, the ones I mentioned. Cite? Joel Whitburn’s “Top Pop Singles 1955-1996 (8th edition)”
Here’s a Library of Congress webpage detailing the origin of the Coca-Cola jingle, “I’d Like to Teach the World To Sing,” which was written by the advertising company.
And here’s another webpage that tells the story of “No matter what shape your stomach’s in,” which confirms Mr. Blue Sky’s assertion that the the song was first a commercial jingle.
I believe the Fifth Dimension song, Up, Up, and Away, was originally a bank jingle. Don’t ask me where I remember this from, though.
It was inspired by a friend’s ballon company and laters used in TWA ads.
OK-we’ve established that some pop tunes were really ad jingles first. Thanks for the enlightenment-I would have called them the other way around.
What’s the answer to my OP?
The winner so far appears to be the Oldsmobile ad.
Some websites I found described the Stephen Foster song “Oh! Susanna” as the unofficial anthem of the California Gold Rush. Does that count?
Perhaps. The song dates from 1905, but when did Oldsmobile start using it in its ads?
According to Exapno’s post, 1908.
Thanks, but credit goes to Monkeyfist.
actually, credit should go to Carrie McLaren, author of the article that I linked to. And also to google, for directing me to the website. But, I’d also like to thank my mom for her always believing in me, and my beautiful wife for being so understanding durring all these late nights away from her, I love you honey. To my daughter, I love you for calling me your hero, and inspiring me to make good on that by making the world a better place for you.