The term 'key players' can refer to two different crossword solutions: pianists (8 letters) and fingers (7 letters). Pianists are musicians who play the piano, a keyboard instrument that produces sound when its keys are pressed. Fingers are the digits of the hand that are used for grasping and manipulating objects. Both pianists and fingers are important components in playing the piano, as the pianist uses their fingers to press the keys and create music.