The music generated in the Orff Approach is largely improvisational and uses original tonal constructions that build a sense of confidence and interest in the process of creative thinking. Students of the Orff Approach sing, play instruments, and dance alone as well as in groups. Songs are usually short, contain ostinatos, are within singing range, can be manipulated to be played in a round or ABA form. "Music is chosen with strong nationalistic flavor, being related to folk songs and music of the child’s own heritage". Music can also be anything from nursery rhymes to songs that are invented by the children themselves. Orff-Schulwerk music is largely based on simple but forceful variations on rhythmic patterns. This makes for very simple and beautiful musical forms, which are easily learned by young children, and is also useful for adults and thus it has a universal appeal. Composer David Hewson was exposed to Orff Schulwerk and this influence helped to shape a lot of his later music.