Hermann Erpf defines 3 ways in which musical form can emerge: he calls them form characters.
- by a sequence of similar but distinctive form sections, as in a song with verse and chorus, a theme with variations: SEQUENTIAL FORM
- by a sequence of form sections, which contains contrasts, with repetition at a distance and a certain balance within the form as a whole: BALANCED FORM, as is the case in a ternary form (A-B-A), Viennese rondo form (A-B-A-C-A-B-A), or in certain sonata forms (exposition-development-recapitulation)
- by avoiding emphasis on segmentation, while using a more processlike approach which is often goal oriented, and which shows signs of a gradual development/change: DEVELOPING FORM; as in minimal music and passacaglia's; and music which makes use of transformational techniques (for example the 1st movement of Carl Nielsen's 5th symphony)
In practice mostly combinations of the three form characters will occur, with an accent on one of them.