production for "A  Night at the Opera," Thalberg kept the Marx Brothers waiting for  several hours in his secretarys office, while he was in his own  office making phone calls. When Thalbergs secretary went home for  the day, the brothers decided theyd had enough. They pushed the  office file cabinets against Thalbergs door, trapping the producer  in his office. Afterwards, Thalberg kept his appointments with the  Marx Brothers, but would often interrupt his meetings with them and  step out to attend other meetings 