When Barack Obama urged Americans to embrace a new spirit of community service, Usher took that message to heart, people.com reports.

The pop star pumped up grade-schoolers and other volunteers with handshakes, jokes and words of praise as they repainted walls and built two libraries at Simon Elementary School in southeast D.C. — an area with a high dropout rate — on the afternoon of Martin Luther King, Jr. Day.

During a feed to Oprah Winfrey’s live show from the Kennedy Center Opera House, the singer talked up the need for volunteerism — even working in a reference to Aristotle — before cuing the kids to yell, “Go serve!” to her audience.