The 1971 TV commercial “Hilltop” directed by Haskell Wexler  featured young people from around the world singing on a hilltop outside Rome, Italy, and was so popular that the song (without the Coke references) became a hit in its own right. Commercial recordings as a pop-song were issued by The New Seekers and The Hillside Singers.

In the commercial, the lead singer and the people surrounding her were filmed lip synching to the New Seekers radio version of the commercial. None of the actors actually sang in the TV version.

The song’s success was particularly notable in the UK where it is one of the 100 best selling singles of all time.

The commercial, as one of the most popular of all time, is credited with helping Coca-Cola regain its status as the preeminent soft drink in North America.

When Coca Cola planned to broadcast this commercial in South Africa on the state-run SABC network, they wanted Coca Cola to use an all-white version, due to the apartheid government. Nevertheless, the commercial was accepted.

“I’d Like to Teach the World to Sing (In Perfect Harmony)” is a pop song which originated as an advertising jingle, produced by Billy Davis and sung by the Hillside Singers, for Coca-Cola, and was featured in 1971 as a TV commercial. The Hillside Singers’ version was released as a successful single the same year; it reached #13 on the Billboard Hot 100 and #5 on Billboard’s Adult Contemporary chart.

The New Seekers also had a hit with the song around the same time.

The song began life as a collaboration by UK hit songwriters Roger Cook and Roger Greenaway. The melody was based on a Cook/Greenway jingle originally called “Mom, True Love and Apple Pie”, ; a version of this called “True Love and Apple Pie” was recorded by Susan Shirley and released in 1971. After a twisting lawsuit the song was reworked by Cook, Greenaway, Coca-Cola with executives Bill Backer, and Billy Davis and recorded as a Coca-Cola radio commercial, with the lyric “I’d like to buy the world a Coke and keep it company.” The idea originally came to Cook and Greenaway while plane delayed at Shannon Airport, Ireland who noticed fellow plane delayed travellers talking and joking over a vending machine dispensed Coca-Cola.

It was first aired as an American radio commercial on February 12, 1971, sparking public demand for its release as a single. Reworked by Bill Backer and Billy Davis to remove the brand name references, the single climbed to UK #1 and US #7 in 1971 and 1972.

The Coca-Cola Company waived royalties to the song and instead donated $80,000 in payments to UNICEF. The song has since been recorded over 75 times.

British band Oasis were sued after their recording Shakermaker borrowed its melody directly; they handed over $500,000 in damages.

Info taken from Wikipedia