Lady Gaga stuns with 'Sound of Music' tribute at Oscars

Lady Gaga - G.U.Y.

Lady Gaga becomes first artist to sell over 20 million digital singles

Lady Gaga - The Fame

This is where you can buy Lady Gaga's pink Joanne hat

Lady Gaga - The Fame The Gaga Collection

Lady Gaga's most iconic looks

Lady Gaga talks about her ever-changing fashion