Aaron Rabushka wrote:

>Don't forget that the ostinato in Bach's passacaglia doesn't always stay in
>the bass.

Having played this work on very many occasions, I was aware of this when I
wrote my little piece.  But I wanted to keep the discussion going.  And Wes
has given a really well thought out answer to it all.

I think any definition of form is bound to have exceptions.  If only
because many composers like to give their own take on a form.  Ultimately
the litmus test is whether the result is good music: I think there can be
little doubt that both the Purcell and the Bach fall into this category.

Jonathan