Korean pop star PSY joined the pop icon Tuesday night during her second show this week at
. They danced to his pop culture anthem "Gangnam Style" and to her jam "Give It 2 ME" in front of nearly 20,000. Madison Square Garden
Madonna said PSY flew "all the way from
this morning." She also said she was a big fan of the rapper and loved his suit, which was bright red. Frankfurt, Germany
He added that he's had a lot of experiences in the last few months, and that performing at MSG with Madonna topped his list.
Madonna also collected money for those affected by Superstorm Sandy. Fans threw money onstage while she sang "Like a Virgin." She said she collected $3,000 at Monday's show.