Superstar Beyonce brought New York City to a standstill on Wednesday when she performed a free concert in the city for hundreds of fans who had turned out to see her perform.The pop singer showed off her sexy curves when she pulled up riding on the back of a chauffeured convertible wearing a body-hugging black catsuit for NBC's "Today Show." Knowles walked down the red carpet, greeting fans who gathered outside the shows Rockefeller Center studios on the way to the stage. She performed a string of hits, including new singles "If I Were a Boy" and "Single Ladies (Put a Ring on It)."Knowles told the crowd, "I just want to say thank you. We have the best fans in the world. They've been supporting me and Destiny's Child since we first came out."