The term CLEF is used in music to refer to a symbol placed at the beginning of a STAFF to indicate the pitch of the notes written on it. The crossword solutions for this term include KEY (3 letters), TREBLE (6 letters), ALTO (4 letters), BASS (4 letters), STAFF (5 letters), ALTOS (5 letters), ROMAN (5 letters), and OBOE (4 letters), VIOLA (5 letters). KEY refers to the musical KEY signature, which is a set of symbols that indicate the tonality of a piece of music. TREBLE is a type of clef that is used to indicate higher-pitched notes. ALTO is another type of clef that is used to indicate middle-pitched notes. BASS is a type of clef that is used to indicate lower-pitched notes. STAFF is the five lines and four spaces that are used to write music notation. ALTOS is the plural form of ALTO. ROMAN is a type of clef that is used to indicate very high-pitched notes. OBOE is a woodwind instrument that is often used in classical music. VIOLA is a stringed instrument that is similar to a violin but has a deeper sound.