After the shouting , he rings the bell again and waves the Flag of Mexico to the applause of the crowd in the Plaza de la ConstituciÃ n. This is followed by the playing and mass singing of the Himno Nacional Mexicano , the national anthem . After the shouting , he rings the bell again and waves the Flag of Mexico to the applause of the crowd , and is followed by the playing and mass singing of the Himno Nacional Mexicano , the national anthem .