Final answer:
Folk music typically operates on the principle of simple repetition, unlike classical, pop, and jazz music, which incorporate both repetition and variation. Folk music's straightforward and repetitive nature is key to its distinctiveness and cultural significance.
Step-by-step explanation:
The work that functions by simple repetition rather than by repetition and variation like common meter is typically found in folk music. Folk music often consists of simple and repetitive structures that convey stories or traditions within a community. Unlike classical music, which often involves complex structures and variations, including the symphony, concerto, and sonata, folk music retains a straightforward and repetitive nature. Moreover, the repetitive pattern of folk music contrasts with the innovative improvisational style of jazz music, which heavily relies on variations and the performer's creative expressions.
In comparison, pop music and jazz music are known for their use of both repetition and variation. Pop music frequently employs a verse-chorus structure with variations in melody and instrumentation, while jazz is characterized by its spontaneous improvisations on top of a theme.