Yoko Ono posted touching tributes to the Beatles legend John Lennon.

“Happy birthday John! Happy Birthday Sean!” Ono wrote in an Instagram comment , wishing her son Sean Lennon a happy birthday. “I love and admire you!” yoko. “

McCartney posted an old throwback photo, with the caption “Happy Birthday @johnlennon. “

Lennon would have turned 81 on Saturday. Last year marked the 40th anniversary of the singer’s death. He was shot and killed on Dec. 8, 1980, as he and his wife, Yoko Ono, were heading toward his New York City apartment building.

Mark David Chapman was convicted of the shooting and is currently in prison.

McCartney posted a tweet to remember the anniversary. “A sad sad day but remembering my friend John with the great joy he brought to the world,” he tweeted. “I will never forget the incredible Scouser I knew and worked with. X loves Paul. “

Ono wrote that the anniversary was a “hollowing” experience. “

“After 40 years, Sean, Julian and I still miss him,” Ono said, referring to Lennon’s two sons.

Minyvonne Burke is a breaking news reporter for NBC News.