At first, fans politely applauded the Roma performers sharing a stage in Bucharest with Madonna. Then the pop star condemned widespread discrimination against Roma, or Gypsies -- and the cheers gave way to jeers.
The sharp mood change that swept the crowd of 60,000, who had packed a park for Wednesday night's concert on the singer's "Sticky and Sweet" tour, underscores how prejudice against Gypsies remains deeply entrenched across Eastern Europe.
Madonna did not react to the crowd and carried on with her concert.
Her publicist, Liz Rosenberg, said Madonna and others had told her there were cheers as well as jeers.
"Madonna has been touring with a phenomenal troupe of Roma musicians who made her aware of the discrimination toward them in several countries so she felt compelled to make a brief statement," Rosenberg said in an e-mail. "She will not be issuing a further statement."