Rihanna kicked off the weekend in New York City! The singer performed on The Today Show's Summer Concert Series wearing a nautical-themed ensemble in tribute to the sailors visiting Manhattan for Fleet Week. Just a few blocks away, Lady Gaga was attired in a not-so-sea-worthy outfit when she stormed Central Park to make an appearance on Good Morning America. In another time zone, Miley Cyrus landed in Mexico City, the latest stop on her Gypsy Hearts tour. Click through the gallery to see all of the stars in the celebratory mood!