A 62 year old woman, has a 3 month history of increasing right shoulder pain. She is now unable to lift her arm to brush her hair or to take a can off a shelf. She denies any numbness or tingling or radiation of the pain down her arm. On physical examination, she exhibits weakness in abduction and external rotation or her right arm. Her shoulder shows a normal passive range of motion. When asked to hold her arms abducted to 90 degrees, she is unable to do so on the right. There is no motor weakness in her forearm or hand. Her right upper extremity has normal pulses and normal sensation. Which of the following muscles make up the injured structure?