What is the formal device used in the aria "Ah! Belinda" and the Mbuti Pygmy "Marriage Celebration Song"?

The correct answer is the ostinato, a formal device characterized by a repeating musical phrase or rhythm. In the aria "Ah! Belinda" from Henry Purcell's opera "Dido and Aeneas," the use of an ostinato is evident in the bass line, which is repeated throughout the piece, creating a sense of continuity and emotional intensity. This pattern underlines the expressive qualities of the music and the text, reinforcing the feelings of despair and longing experienced by the character.

In the Mbuti Pygmy "Marriage Celebration Song," the ostinato is also a key element as it forms the foundation upon which the other vocal lines are built. The repetition of a particular phrase allows for elaborate variations and embellishments by the performers, contributing to the communal and celebratory atmosphere of the song.

The presence of an ostinato in both examples highlights the importance of repetitive structures in creating musical coherence and depth, making it a significant formal device in diverse musical traditions.