A chain shift may affect only one regional dialect of a language, or it may begin in a particular regional dialect and then expand beyond the region in which it originated. A number of recent regional chain shifts have occurred in English. Perhaps the most well-known is the Northern Cities Vowel Shift, which is largely confined to the "Inland North" region of the United States. Other examples in North America are the California vowel shift, Southern vowel shift (in the Southern United States) and the Canadian Shift. In England, the Cockney vowel shift among working-class Londoners is familiar from its prominence in plays such as George Bernard Shaw's "Pygmalion" (and the related musical "My Fair Lady"):