I do believe it might have actually been Elton John, waaaayyy back in the 80's. I could be wrong, but it was someone *similar* to that genre. I was only 13 and was taken by my godparents, it wasn't exactly the wildest of nights.
The first one I REALLY remember (and that I bought my own ticket to) was the massive Guns & Roses, Skid Row and Rose Tattoo concert at Calder park in Melbourne in 1992 - it was wicked, 100,000 + people in a festival-style outdoor atmosphere, all banging heads in synchrony... my little 16-year-old mind was blown away :D