the shows they have in melbourne are (these are the major ones):
MELBOURNE MOOMBA FESTIVAL (MARCH)
ROYAL MELBOURNE SHOW (SEPT)
LYGON ST FESTA (NOV)
RYE CARNIVAL (DEC-JAN)
and then there are many regional fairs with few rides
also there are state shows (at the moment the royal easter show is on in sydney)
the rainbow operates at the state fairs, and then every second year at the rye carnival, moomba used to be good, except this year was crap because there was crap all rides