In 2009, Ajani Boyd was among the mass of humanity that traveled to D.C. to witness the inauguration of President Obama. That was memorable, but this week the 11-year-old Dorchester native was actually in the White House. Boyd, who attends Boston Latin School, was in the East Wing to receive an award on behalf of Project STEP (Strings Training and Education Program). “It was a little nerve-racking,” Boyd admitted Wednesday. Especially since it was First Lady Michelle Obama who presented him with the National Arts and Humanities Youth Program Award. “She hugged me and talked to me in kind of a quiet voice, saying ‘How do you like being in the White House?’” Project STEP, a year-round classical string training program for minority children, was chosen for the award from 50 finalists. Boyd plays the double bass.