Dave Pitzer wrote:

>Mr. Schwartz may "suggest" that there are two kinds of rests but that
>doesn't make it so.  A rest is a rest is a rest.

How long do you hold a rest with a fermata? That's a prime example of an
inexact rest, especially when there are fermatas over different note values
in different parts in the same measure.  There are other situations as
well, some of which I've mentioned in a longer post, and all drawn from
actual examples of music.  So it really isn't my suggestion (sneer quotes
noted) after all.

>And to ignore, shorten, lengthen (in context) any rest is the same as
>treating notes the same way.

There are also notes that are held inexact durations, particularly in
20th-century music.  You want specific examples? How about the storm and
prayer scene in Gershwin's Porgy and Bess, where each character in effect
prays at his own speed?

>Rests at the end of a piece are there to "finish" the final measure from a
>counting, mathematical or technical aspect.  Take Brahms' "Variations on a
>Theme by Joseph Haydn".  The opening Choral (after several [essential]
>repeats, incidentally) end in a full measure rest to the entire orchestra
>-- except the cellos and bouble basses.  These have a single quarter not
>--- followed, of course, by a quarter REST.  That makes it all "end" at
>the same time from a technical aspect.  (I use this particular example
>since it is open on my desk at the moment.)

Yes, these are examples of exact rests, always allowing for the desideratum
that music made by humans isn't mechanically exact.

Steve Schwartz