Vocal style is a term used to describe the way a singer expresses themselves through their voice. Arioso, a 6-letter term, is a lyrical vocal style that combines elements of both singing and speaking. It is often used in operatic music and is characterized by its expressive and melodic nature. SCAT, a 4-letter term, is a vocal improvisation technique that involves singing nonsense syllables and words. It is often used in jazz music and is characterized by its rhythmic and playful nature.