I just added two more festival book images to the 17th century timeline (1st half). They could really be included in the previous century, since they are documenting an event from 1596, but I included them in the 17th because that’s when the record was actually published. I had the first of the three below images in the timeline already; the bottom two are new. I’ve included the timeline caption here as well:
1601—Wolfenbüttel, Germany: A festival book for Landgrave Moritz of Hesse-Kassel documenting the 1596 celebrations in honor of the baptism his daughter, Elizabeth, includes at least three different images (by artist Wilhelm Dilich) of trombones in musical ensembles walking in procession (see below images; public domain) (Dilich 00135). The bottom image is somewhat unusual for its inclusion of two trombones in such a small ensemble.