Rhythm and blues diva Beyonce will sing three songs from Oscar-nominated movies at this year’s Academy Awards, organisers announced. In addition, Oscar-winning actor Robin Williams will join the growing list of celebrity presenters of statuettes at February 27th ceremony. Beyonce and crooner Josh Groban will sing the Oscar-nominated film song “Believe” from “The Polar Express,” while Beyonce will perform “Look to Your Path” from “Les Choristes” and “Learn to Be Lonely” from “The Phantom of the Opera.” The group Counting Crows has also signed on as an Oscars act and will perform their nominated song “Accidentally In Love” from the movie “Shrek 2.” Beyonce, Groban and Counting Crows are the first musical acts to be announced for the show. Williams, who won a best supporting actor Academy Award for 1997’s “Good Will Hunting,” joins a host of other stars who will be handing out the golden statuettes later this month.