This is interesting. Personally, I have never heard of the trombone being used in the Baroque Era, so it is of interest to me that trombones did exist in that period of time, and furthermore they were used in various pieces (though these Baroque pieces are not commonly performed nowadays, inasmuch as I know). Usually, we are taught that the trombone was officially part of the orchestra in the Romantic Era, so thank you for this food-for-thought.