The term 'HIGH RANGE' is used to describe the uppermost range of notes in music. It can refer to both vocal and instrumental ranges. The two crossword solutions for this term are 'TREBLE' (6 letters) and 'SOPRANO' (7 letters). TREBLE is a musical term that refers to the highest range of notes in a piece of music, usually played by instruments such as violins or flutes. SOPRANO is a vocal range that is the highest of the female voices, and is often used in operas and other classical pieces.