Ann-Margret largely improvised the infamous bean scene. Director Ken Russell simply told her that her character was having a nervous breakdown, and that she could do whatever she wanted. Unfortunately, at one point during filming, her hand accidentally struck the broken glass of the television screen, and Russell had to rush her to the hospital for stitches.
According to Pete Townshend, Oliver Reed had incredible problems recording his part of the soundtrack owing to his inability to sing, and he was able to complete it only because his singing parts were recorded in small bits. Because of this frustrating experience, Townshend was extremely suspicious towards Jack Nicholson when he was chosen to the role of the doctor. Townshend, however, finally agreed when he heard Nicholson singing effortlessly.
Ann-Margret won the Best Actress Golden Globe for her performance, was nominated for the Oscar, and remains to this day the only actress ever Oscar-nominated in the lead category for a performance which is (save for one single word) entirely sung.
The building that is seen to be on fire, part of Tommy's holiday camp, is really burning down. It is South Parade Pier in Southsea. A fire was accidentally started during filming, and the crew decided to include the footage in the film. The fire crews and the fire are genuine. The pier was rebuilt and is still in use.
Barry Gibb: Person who pushes one of the wheel chairs during "Eyesight to the Blind/Marilyn Monroe" sequence.
Ken Russell: One of the disabled people during the Eyesight to the Blind sequence. He also can be seen in the Tommy's Holiday Camp sequence in the junkyard at the end of the film. He's in a wheelchair.
Ken Russell: [colors] Colors of sets during "Acid Queen", "Cousin Kevin", and "Uncle Ernie" sequences; lighting during "Pinball Wizard".