Oh My Girl returned to the old school days on the July 15 composer Park Shi Choon special of 'Immortal Song'.
SEE ALSO: Oh My Girl confirm their comeback date
In '60s school uniforms, Oh My Girl covered Baek Nan Ah's 68-year-old song "Sweet 18", which is a perfect song for the rookie girl group. Before performing on stage, Oh My Girl said, "It's a song released in 1949, but all our members knew it," remarking on the longevity of the song.
The audience loved Oh My Girl's throwback to the old hit as well as their stage outfits, but it was married couple Yoo Sung Eun and Bong Goo who took the final win.
Original song from 1949: