Step 1 : Introduction to the question "7. Who provided security at the Rolling Stones' 1969 Altamont concert? "
...1. Royal Canadian Mounties 2. Rent-A-Cop 3. Hells Angels 4. Vienna Boy's Choir Accounts vary as to whether the Hells Angels were hired by the concert promoters or the Rolling Stones, or if they just showed up and took matters into their own hands.
