The term 'SOPRANO's Highlight' is a reference to an ARIA, which is a type of solo song typically found in operas. An ARIA is usually sung by a SOPRANO, the highest-pitched female voice in opera. The crossword solution for this term is 'ARIA, ' which is an acronym for 'Air with Instrumental Accompaniment.' This term is used to describe a type of musical composition that features a solo vocal line accompanied by instruments.