Video: 'Marilyn Monroe-Happy Birthday Mr. President'

(Saturday, May 19, 1962, just before JFK began speaking at 11:30 p.m. EDT) — Actress Marilyn Monroe, accompanied by jazz pianist Hank Jones, performed a sultry rendition of Happy Birthday to You tonight for guest-of-honor President John F. Kennedy before 15,000 people attending a star-studded Democratic fundraising gala at New York’s old Madison Square Garden.

Monroe sang the traditional “Happy Birthday to You” lyrics with “Mr. President” inserted as Kennedy’s name.

The event was billed as a celebration of Kennedy’s 45th birthday, held 10 days before the actual date (May 29). First Lady Jacqueline Kennedy, who rarely attended Democratic Party events, spent the day at the Loudon Hunt Horse Show with her children, John and Caroline.

Video: 'This Marilyn Monroe Dress Stole the Show at JFK's Birthday Party'

Staged and produced by Broadway composer and lyricist Richard Adler, the show was hosted by Kennedy’s brother-in-law Peter Lawford and featured performances by numerous celebrities including Ella Fitzgerald, Bobby Darin, and Maria Callas.

Throughout the evening, Lawford played on Monroe’s reputation for being late to build anticipation for fever-pitch. When she shimmied across the stage and removed her fur coat to reveal a figure-hugging, flesh-colored gown covered with more than 2,500 rhinestones, designed by French-born costume designer Jean Louis, the room erupted.

Video: 'JFK'S SPEECH AT HIS BIRTHDAY CELEBRATION AT MADISON SQUARE GARDEN IN NEW YORK CITY (MAY 19,...'

After performing “Happy Birthday To You,” Monroe segued into an adapted version of “Thanks for the Memory” that celebrated Kennedy’s political achievements. She was on stage for barely two minutes and was followed by the President himself alongside an enormous birthday cake.

Kennedy then followed with an address, joking that he could “retire after having had ‘Happy Birthday’ sung to me in such a sweet, wholesome way.”

Monroe’s performance was one of her last major public appearances before her death less than three months later on Aug. 4, 1962.