I agree with your review - in fact, you are being pretty kind. The quality of the Mountain Play annual musicals has gone way down for close to 10 years. BTW, the gimmick of planes flying over head and the use of the jeep in South Pacific have been done 5 times now (back to the 1990s productions of South Pacific). But gimmicks do not justify the poor quality of the acting, singing and dancing and certainly do not justify those ticket prices.
