Lady GaGa had her "first real Marilyn Monroe moment" when she performed at the 10th anniversary of Bill Clinton's foundation last night (15.10.11).

The 'Born This Way' hitmaker sported a wavy blonde hairstyle and red lips - in a similar style to the late actress, who famously sang "Happy Birthday, Mr. President" to President John F. Kennedy in 1962 - and wished Clinton "Happy Birthday" before making a number of references to him as she performed at the Hollywood Bowl concert.

She joked: "Bill, I'm having my first real Marilyn moment! I always wanted to have one, and I was hoping that it didn't involve pills and a strand of pearls."

Gaga changed some of her lyrics to refer to the former US president - who turned 65 on August 19 -including swapping the title of her hit song 'Bad Romance' to 'Bill Romance'.

The politician sat next to his Secretary of State wife Hillary at the 'A Decade of Difference: A Concert Celebrating 10 Years of the William J. Clinton Foundation' event - which also saw performances by Stevie Wonder, Usher and U2's Bono and The Edge - and he praised his other half's charity work.

He said: "I want to thank Hillary because we met 40 years ago this year. When I met her, she was already doing the kind of work you see here long before it was cool."

The foundation aims to improve global health, strengthen worldwide economies and promote healthier childhoods.