This is probably supposed to be campy.  Imagine the following ingredients: two dudes who look like refugees from a 1977 Foreigner tour, a set of drums, a guitar, Tia the ex-rocker groupie, and a very busty Sunshine, who could probably play the drums with her low-slung tits.  All of the above are involved in doing one another in a backstage, grungy sort of way.  Peace, man!  Free love!