Jonathan Ellis wrote:

>Wes Crone wrote:
>
>>As far as I have learned through my own studies:
>>Chaconne: Common harmonic sequence throughout.
>>Passacaglia: common melody throughout; usually in the bass but not always.
>>Ground: Unwavering bass line, never changes; music changes above it.
>
>This would make Bach's organ Passacaglia a Ground.  Are you suggesting that
>Bach got it wrong? ;-)

This would NOT necessarily make Bach's piece a ground.  If you look at
my simple, condensed definitions you can see that they kind of overlap
regarding the Passacaglia and the ground.  As I defined them, Bach's
famous Passacaglia could be called either or.

One thing to think about though, at the opening of Bach's piece all we hear
IS the main melody which later becomes the constant bass line.  This is
consistent with other Passacaglia in that the main melody isn't necessarily
confined to play "under" all the other music.  In this case the bass line
IS the melody for some part where in a ground the bass line is essentially
NEVER the melody but the repeating harmonic backdrop/bass line.

it is interesting to note that in Purcell's wonderful ground, (Dido's
lament) the bass line is presented at the beginning alone as in the
Passacaglia by Bach.  Maybe the piece is a Passacaglia.  Maybe not.
Point is, Purcell called it a ground and since we have no concrete
definitions his choice of word will have to do.

Clearly, in Bach's famous Passacaglia, the main line is the star of
the show even with all the wonderful stuff Bach does with it; in the
later sections Bach REALLY emphasizes the continuous motif.  This simply
isn't the case with Dido's lament where the gorgeous melody is given the
spotlight.  I think ground and Passacaglia are MUCH more interchangeable
than Chaconne and Passacaglia.  This is of course, just an opinion, but
I think I have clearly described why I have this opinion.  Hope this has
cleared away some of the clouds I brought with me.

--Wes Crone