WASHINGTON — Crediting civil rights-era protest songs and their spiritual predecessors for his election, President Barack Obama on Tuesday sat in the East Room of his White House and listened to an all-star lineup of performers pay tribute to the music that he said fueled freedom marches and civil disobedience. The nation's first black president transformed the grand ballroom into a concert hall packed with members of his Cabinet, Congress, civil rights leaders and students for a program that will air on public television later this week for Black History Month.