Singers Stevie Wonder, left, Gladys Knight, Elton John and Dionne Warwick perform their hit song "That's What Friends Are For" at amfAR's annual New York Gala at Cipriani Wall Street on Wednesday, Feb. 9, 2011 in New York. amfAR, The Foundation for AIDS Research, is celebrating it's 25th anniversary this year. (AP Photo/Evan Agostini)