AriaIn music, an aria (Italian: ˈaːrja; plural: arie ˈaːrje, or arias in common usage, diminutive form arietta aˈrjetta, plural ariette, or in English simply air) is a self-contained piece for one voice, with or without instrumental or orchestral accompaniment, normally part of a larger work. The typical context for arias is opera, but vocal arias also feature in oratorios and cantatas, or they can be stand-alone concert arias. The term was originally used to refer to any expressive melody, usually, but not always, performed by a singer.
QuartetIn music, a quartet (quatuor, Quartett, quartetto, cuarteto, kwartet) is an ensemble of four singers. String quartet In classical music, one of the most common combinations of four instruments in chamber music is the string quartet. String quartets most often consist of two violins, a viola, and a cello. The particular choice and number of instruments derives from the registers of the human voice: soprano, alto, tenor and bass (SATB).