Perhaps the first awareness of postmodernism was in the field of architecture. It is in architecture that the multifarious manifestations of postmodernism are most clearly visible and, therefore, most easily described. In architecture, postmodernism is a comparative concept, as it is in general, and therefore it must be contrasted with modernism. Postmodernism is not the opposite of modernism, as it is often portrayed, but is rather broader, more inclusive, and encompasses modernism within it. As such, postmodernism seems to represent a period of transition, a period in which a uniform aesthetic has not yet matured.
Dates can only be artificial divisions, but they are useful as guidelines.
Modern music is generally considered to be a period from about 1910 to 1960, with 1960-70 being a transitional stage. Modern composers include Schoenberg, Bartok, Varese, and Stravinsky. Postmodern composers include John Zorn, and Frank Zappa. But, Charles Ives was, in some ways, a proto-postmodernist who lived early in the century, which demonstrates that dates cannot be relied upon completely. On the other hand, modernism survives today as late-modernism, with such composers as Pierre Boulez, Milton Babbitt, and Karlheinz Stockhausen.