Most shows match bands with a similar sound. The band opening usually having the smaller fan base due to their relative inexperience or what-have-you.
In recent years it's sometimes been fashionable to mismatch the bands. Ordinarily with less than stellar results. I remember one of the few Nine Inch Nails fans who stayed for Bowie's set remarking how clever Bowie was to sing a Nirvana song. I couldn't see the advantage of pointing out who did MWSTW first, and simply nodded in agreement. My point here isn't to slag a youngster, but that the meshing of the generations failed terrifically.
Last year the Mars Volta opened for the Pixies with marginally better results.
And those of us in L.A. are fond to remember Prince getting booed off the Rolling Stones stage those many years ago, now.
*What sort of mismatches work, and which ones don't? Why? Offer specific examples and suggest possible shows you think would work.*
Either that or ignore this thread completely and risk a failing grade on your permanent record.