Katharine McPhee has married music mogul David Foster in London. E! News reported McPhee, 35, and Foster, 69, exchanged wedding vows on Friday at the church of St. Yeghiche. "It was a very quick but traditional ceremony," the outlet quoted an unnamed source as saying. "Katharine looked stunning in a classic Zac Posen simple white gown." People.com said the singer, actress, and former "American Idol" runner-up changed into a blue, strapless gown for the wedding reception that followed the ceremony. McPhee tweeted Friday: "Exactly 13 years ago today my very first single, Somewhere Over The Rainbow, was released right after Idol. Today... I'm marrying the man who produced it." "Life is full of beautiful coincidences, isn't it? Thank you for taking me over the rainbow, David." The couple announced its engagement last summer.