A key player is someone who is essential to the success of a team or organization. In this case, the two crossword solutions for the term 'key player' are organist (8 letters) and STAR (4 letters). An organist is someone who plays the organ, which is a keyboard instrument with pipes that produces sound. A STAR is someone who stands out from the crowd due to their exceptional talent or skill. Both an organist and a STAR can be considered key players in their respective fields.