"Round and Round" is by no means an original piece created for "Squid Game." Rather, it's a popular Korean kids' song penned by composers Jeon Jeong-geun and Dr. Lee Soo-in that dates back decades.

Song, fresh off her turn in Lunar New Year release “Dark Nuns,” leads the ensemble cast alongside “Squid Game” star Gong Yoo, who portrays her childhood friend Dong-gu. Their characters ...