School of Rock, the musical written by Andrew Lloyd Webber and Julian Fellowes, opened Sunday night on Broadway.<br />"School of Rock is fun," Lloyd Webber says.<br />"Hopefully, I've fleshed it out with a few catchy songs and kept the spirit of the original movie.<br />Hopefully, it's something that you will go to and say, 'I had a really good time,' but hopefully, you will also take out of it the central message of the story, which is a very warm and very simple one, which is about the empowering force of music."<br />The creative team has fleshed out the characters of the children and their relationship with their parents, says Downton Abbey creator Lord Julian Fellowes.<br />These days, with such hit musicals as Annie and Matilda , seeing kids who can act and dance and sing is nothing particularly new, but seeing them actually play their instruments may be the show's biggest appeal, says Lloyd Webber.