I saw Canned Heat in 1972(?) in concert at the auditorium of the university I was attending. The crowd did not consist of dedicated hard core blues fans though and Canned Heat became frustrated with the lack of response after a few numbers. They shifted gears and played "Wooly Bully" to which the crowd responded enthusiastically but before the end of the show Bob "The Bear" or one of the other fellows ended up lecturing the crowd about having come to the concert if they weren't into the blues.
The problem though was that Canned Heat's hit singles, "On the Road Again", "Going Up the Country" and "Let's Work Together" were not really representative of the band's style of music.