During "A Decade of Difference: A Concert Celebrating 10 Years of the William J. Clinton Foundation," Lady Gaga serenaded the First Family of the 90s by altering the lyrics to her biggest hits to pay tribute to Bill and Hillary Clinton. 

Celebrating 40 years of marriage -- and a good 12 years of avoiding all reference to a certain beret'd intern -- this year also marked Bill's 65th birthday. To wit, the Lady slipped into her best Marilyn Monroe schtick to sing "Happy Birthday, Mr. President."

As if further reason was needed to celebrate, the concert was also to raise awareness about the Clinton Foundation's humanitarian do-goodery around the world.

In addition to getting caught up in a "Bill Romance," Gags claimed the former president was "Bill This Way" and referenced Hills in "Yoü &I":  "Sit back down where you belong in the Oval Office with those high heels on."

Video of the entire concert, featuring performances by Stevie Wonder, U2, Usher is available at Yahoo!