This constant introduction of new material is most noticeable in musical settings of poems, in contrast to the often used strophic form (AAA).
[2] Musicologist James Webster defines through-composed music in the following manner: In general usage, a 'through-composed' work is one based on run-on movements without internal repetitions.
)[3]Many examples of this form can be found in Schubert's lieder, in which the words of a poem are set to music, and each line is different.
This stands in contrast to the practice, as for example occurs in Mozart's Italian- and German-language operas, of having a collection of songs interrupted by recitative or spoken dialogue.
In musical theater, works with clear delineations between songs yet no spoken dialogue – such as Les Misérables or Hamilton – are usually instead referred to by the term "through-sung".