Let's say the 2012 election was a talent competition, based on singing. Who would you vote for?President Obama and one of his Republican rivals, former Massachusetts Gov. Mitt Romney, showed off their singing skills on Thursday. (watch at left) At his campaign headquarters in Charleston, S.C., Romney asked the crowd to help him sing "Happy Birthday" to South Carolina Gov. Nikki Haley. Later that night, during a fundraiser at the famed Apollo Theater in Harlem, President Obama surprised the crowd by of Al Green's hit, "Let's Stay Together." (Watch more of Obama at the Apollo) After hitting a high note in the song, "I...I'm so in love with you," Mr. Obama smiled at the crowd then joked the "Sandman" didn't come out -- a reference to the late Howard "Sandman" Sims, an Apollo fixture who would usher bad acts off stage.