When was the arena, at which the first Summadayze festival was held, officially opened ?
Summadayze:  The first event occurred on 1 January 1998 at the Sidney Myer Music Bowl in Melbourne. Sidney Myer Music Bowl:  It was officially opened by Prime Minister Robert Menzies on 12 February 1959, with an audience of 30,000 people, and is listed on the Victorian Heritage Register.
12 February 1959,