10/12/2011 at 09:00 AM EDT
Looks like Michael Jackson
's kids inherited his dance moves.
Backstage at Saturday's Michael Forever tribute concert
at Cardiff's Millennium Stadium, Blanket Jackson, 9, was a dancing machine.
"Blanket was dancing and spinning – and it was like an exact Michael Jackson dance," says a source who was backstage at the show and saw all of Jackson's children
, including Prince, 14, and Paris, 13, hanging out.
"All three of the kids were in one of the little quick change rooms backstage," the source continues, "but Blanket was dancing on his own."
Typically shy, Blanket looked like "he was happy," says the source, who adds: "The kids were watching him and joking around."