In Dulce Jubilo

I posted this one a few years ago on the Metz and thought it would be a good idea to use a real baroque organ this time.
So here it is.
Some presume it is the result of writing down an improvised choral prelude.
Bach was once reprimanded, that his preludes were too long, after which he shortened them so much, that he got in trouble again.
A man after my own heart!