A poem is any work of art that exploits some of the musical characteristics of language, such as meter, rhythm, euphony, and rhyme  A novel, though it may be a work of art in language, does not usually exploit the musical characteristics of language  A symphony, though it may be a work of art that exploit the musical characteristics of sounds, rarely involves language
A limerick, though it may exploit some musical characteristics of language, is not, strictly speaking, art
Limericks constitute a nonartistic type of poetry.