But he did not turn up, and the other four singers had to perform the song at The Float@Marina Bay without him.
Shin Min Daily News last Saturday reported industry sources as saying that his absence was because he had failed to reach a settlement on his singing fee with YOG organisers.
When contacted, Mr Andrew Jones, vice-president of global marketing at Sony Music Asia, said: "The delay was caused by a passport mix-up and we strongly refute speculation...that Sean Kingston's absence was to do with fees."
The singers are managed by Sony Music, except Nauser, who is managed by Hype Records. Last Saturday, Kingston tweeted about his no-show, saying that he was unable to attend the opening ceremony "due to circumstances beyond my control".
"This music industry is all business but I refuse to let my Singapore fans suffer. I love u all and trust me being a part of the YOG meant a lot," he tweeted.
He added: "I sincerely apologise to all the fans who were expecting to see me... I will try my best to make it up to you all as soon as possible."
In an interview with my paper last Thursday, the four singers were rather nervy when asked casually about Kingston's absence. They exchanged glances and laughed nervously before Appleton cautiously said: "I think... he's busy."