TORONTO (Reuters) - The "Lord of the Rings" musical, touted as the most expensive stage production yet, met mixed reviews on Friday as critics applauded its leaping orcs and menacing dark riders, but got lost in the tangled plots of Middle Earth. The 55-strong cast slipped into 500 costumes and engaged in fight scenes and acrobatics atop a 40-ton, computer-controlled stage floor featuring 17 elevators, which spun and rose amid magic and illusion. For all the feverish activity at Toronto's Princess of Wales Theatre, the show based on J.R.R. Tolkien's epic trilogy drew only one standing ovation in more than...