Officials rang bells, cut ribbons and gave "it's-going-to-be-a-great-school-year" speeches.

Then Arlene Ackerman, superintendent of Philadelphia schools, told the hundreds of underclassman at Oxford Circle's brand-new Fels High School to ask for a real first day of school treat.

"We want a rap! We want a rap!" the crowd told Mayor Nutter.

Fresh from taking his own daughter to her first day of high school at Masterman High in Spring Garden, the city's rapper-turned-mayor obliged, if a bit reluctantly.

"Come to school, don't be a fool," Mixmaster Mike rhymed. "You gotta stay in school if you want to graduate."

Around the city, 160,500 public school students returned to classes this morning. Ackerman, Nutter and others gathered at Fels for a bell-ringing ceremony.

The superintendent started her day by visiting the family of Mo'Naire Walker, 14, a Fels freshman who lives a few blocks from the school.

Mo'Naire and his younger brother and sisters sat around the family's dining room table before the superintendent walked the ninth grader to school.

"You've got to set goals every year, and try to accomplish them," Ackerman said. "You've got to bring home good grades."

Meanwhile, at Northeast High School, actor Tony Danza reported for his first day of school as a co-teacher of an English class as part of a reality TV show.

Many of the students' parents probably remember Danza best for his roles in "Taxi," and "Who's the Boss," but the big question was how many of the students - if any - had any idea who he was before he signed on to teach.

It also was the first day of school for districts outside the city that did not open their doors last week.

The Archdiocese of Philadelphia's parochial schools open tomorrow.