David Arditti wrote:

>The fact is that there <is> such a thing as common practice music,
>more commonly known as "classical music", in the broad sense, hence
>the title of this list, which is not an invention of theorists, but is
>audible to listeners with no technical understanding of music whatever as
>a consistency of language spanning the music of the early renaissance to
>the late romantic; and the same listeners can clearly hear that modernist
>music is fundamentally different, being a series of unrelated experiments
>in arbitrary directions establishing no new common practice of its own.

Please do tell me the origin of a notion that equates common practice to
"classical music."

While I do not know of the origin of the phrase, "common practice," I do
know of the phrase from the writings of Walter Piston.  "...that theory
must follow practice, rarely preceding it except by chance, we must realize
that musical theory is not a set of directions for composing music.  It is
rather the collected and systematized deductions gathered by observing the
practice of composers over a long time, and it attempts to set forth what
is or has been their common practice...Historically, the period in which
this common practice may be detected includes roughly the eighteenth and
nineteeth centuries." On the same page Piston writes, "The experimental
period of the early twentieth centruy will appear far less revolutionary
when the lines of development from the practice of older composers become
clearer by familiarity with the music."

Karl