Lady Gaga serenades ex-US president Bill Clinton in a Marilyn Monroe moment

The 25-year-old took to the stage at Los Angeles' Hollywood Bowl on Saturday night at a concert to mark Bill's belated 65th birthday and the 10th anniversary of his Clinton Foundation.

Emerging from an all-white treehouse, Gaga, real name Stefani Germanotta, sported a wavy blond hairdo and red lips like Monroe, who famously crooned Happy Birthday, Mr President to John F Kennedy in 1962.

The singer changed the words of her hit song Bad Romance to Bill Romance in honour of Clinton.

Gaga then went on to say that she 'always wanted' to channel Marilyn, adding: 'I was hoping that it didn't involve pills and a strand of pearls.'

Clinton, whose birthday was on August 19, said in a short speech in the middle of the show: 'How cool is it to be 65 and you get Lady Gaga, come on?

'And then I wondered... she said she was going to have a Marilyn moment, I thought, by God I get Lady Gaga and I will have a heart attack celebrating my 65th birthday.'

Other performers at the show included Stevie Wonder and Usher.