A description of a Buxtehude service that Bach attended in his famous 4-month AWOL from Arnstadt.
The musical presentations included both large organs and featured several instrumental and vocal choirs positioned in different galleries; and the end, at least of Castrum doloris, had the entire congregation join in as well. …The instrumental requirements as outlined in the librettos are particularly striking and were apparently without precedent or parallel. The intradas require two bands of trumpets and timpani, a ritornello “two choirs of horns and oboes,” a sinfonia “twenty-five violins in unison,” and a passacaglia “various instruments.” (Christoph Wolff, Johann Sebastian Bach: the Learned Musician)
Unfortunately, the Buxtehude scores themselves are lost. Still, a stirring description.