MAYOR NUTTER, burdened with the violence of 20 homicides in Philadelphia's first 15 days of 2012, was due at the podium for today's 30th annual Martin Luther King Jr. Day luncheon.

But master of ceremonies E. Steven Collins was asked to add a surprise speaker to the roster.

And as hundreds of people ate their lunches and spoke with old friends, the words of President Obama began emanating from the stage. People stopped buttering rolls and looked up.

Obama wasn't there. But a reasonable facsimile was. Serigne Fall, a tall and slender 17-year-old from Germantown, delivered about one-third of the famous speech Obama made in Chicago's Grant Park in November 2008, after winning the general election.

The teen, a protege of City Councilman Kenyatta Johnson since the 2008 presidential campaign, was spot-on with Obama's inflection and body language.

Nutter embraced Fall and called for more applause.

And then Nutter spoke about the crime and violence that continues to plague the city.

"Put down the weapons; pick up an application," Nutter implored. "Put down the weapons; go to school. Put down the weapons and let all of us live in peace and harmony in that beloved community that Dr. King strove for and talked about and fought for."

U.S. Sen. Bob Casey Jr. told Malaak and Ilyasah Shabazz, two daughters of the late civil-rights leader Malcolm X, about having read their father's autobiography during his days as a volunteer teacher in North Philly in 1982 and 1983. Casey said the book helped him realize "some fundamental truths about what it means to live in the inner city."

The Shabazz sisters were among six "drum majors" honored at the event - people whose deeds exemplify King's ideals. The others: actress Sheryl Lee Ralph; Daniel L. Hilferty, president and CEO of Independence Blue Cross; former Judge Renee Cardwell Hughes, CEO of the southeastern Pennsylvania chapter of the American Red Cross; and civil-rights activist Rosalee Smith.

"I would suggest that in different ways and in very different walks of life, each of these folks demonstrates a commitment to public service, to equality, to human rights, for caring for people who were less fortunate," U.S. Sen. Pat Toomey said in congratulating the drum majors.