Robert Cuccioli, set to star in The Secret Garden at Sacramento Music Circus in August but best known for playing the tormented title characters in Jekyll and Hyde has a much cheerier assignment July 2. He'll be at Central Park's Naumberg Bandshell singing the Star Spangled Banner as a welcome to 500 new American citizens being naturalized in a ceremony that Friday morning. A police band will accompany the proceedings, to be conducted by Commissioner Henry J. Stern and Court Judge Harold Baer Jr. -- By David Lefkowitz