The term 'SCORE SYMBOL' in a crossword puzzle refers to the symbols used in musical notation. The four solutions are REST (4 letters), NOTE (4 letters), CLEF (4 letters), and GCLEF (5 letters). A REST is a symbol that indicates a period of silence in a piece of music. A NOTE is a symbol that indicates the pitch and duration of a sound. A CLEF is a symbol that indicates the pitch range of a piece of music. A gclef is a variation of the CLEF symbol that is used to indicate higher pitches.