Yeah, openers can sometimes be anticlimactic. Like the historically famous Jimi H opening for the Monkees. Or, in my personal experience, Janis Joplin opening for the Chambers Brothers(1969), or Chuck Berry opening for the Lovin' Spoonful (~1967). I can justify Joe Walsh and the James Gang opening for Santana(1969), and certainly The Staples Singers opening for the Doors(1970).