Final answer:
The song 'Swing Low, Sweet Chariot' is based on the pentatonic scale, likely the major pentatonic, which consists of five notes that give it a distinctive, open sound typical of spirituals.
Step-by-step explanation:
The scale used in the song Swing Low, Sweet Chariot is the pentatonic scale. This is evident from the melody which primarily uses five notes that fit within the framework of a pentatonic scale. Often in the context of African American spirituals, the melodies are constructed using this type of scale due to its simple, but expressive nature.
The pentatonic scale in the case of this song is likely to be the major pentatonic scale, which consists of the first, second, third, fifth, and sixth notes of the traditional major scale. This creates a sequence of notes that provides a sense of openness and accessibility, which is characteristic of many folk and spiritual songs, including Swing Low, Sweet Chariot.