Does anyone know ehre the tour buses for the bands playing at HOB usually park?
There's a secured "underground" parking lot for all the service and delivery vehicles underneath part of Downtown Disney, I think you get in at the low part of Disneyland Drive. You can get a glimpse of it through the fence while riding the M&F tram into the resort. I'll bet they park the tour buses down there in the "open air" section, where they can get satellite coverage for their DirecTV.
Secured being a key word in that last paragraph. You aren't getting down there unless you have a good reason, and "band groupie" or "Papparazzo" doesn't cut it...
I could possibly BS my way in, since I drive a quite obvious "work truck" doing field service myself. But I'll bet you the guards call and confirm the paperwork you present with the store you claim to be servicing before they let you in, which would put a fast stop to that.