This undated publicity image originally released by United Artists shows Sylvester Stallone posing in character as Rocky Balboa in the boxing film, "Rocky." It's been a knock-out in Germany. Now Stallone hopes a musical based on his beloved boxing film Rocky will also be a hit on Broadway. Producers say they hope to get Rocky up and punching at the Winter Garden by February following a successful debut in Hamburg last fall. Based on the Oscar-winning 1976 film, the musical features a score by Ragtime veterans Stephen Flaherty and Lynn Ahrens, and a story by Thomas Meehan, who wrote The Producers and Hairspray.