Added the below image by Balen to the 17th century (first half) timeline. The concentration of paintings from this time period that feature trombone is really remarkable.
c. 1615—Antwerp, Belgium: Hendrick van Balen’s painting, Minerva among the Muses, on the cover of a virginal belonging to Queen Maria Kazimiera Sobieski, features a trombone among several instruments resting on the ground. The trombone is somewhat unusual because of the double loop of tubing on the back of the instrument. Queen Maria, originally from Poland, marries King James Stuart and spends most of her life in Rome. Hendrick van Balen, the artist, is a mannerist from the Antwerp School (see facing detail and full image, below) (source: wikimedia commons).
It is probably not a coincidence that another Flemish painting from the same time period, this one a collaboration by Jan Brueghel the Elder and Peter Paul Rubens in 1617-18, shows a trombone in a nearly-identical position, with the same double-loop. The two string instruments laying across each other nearby are also nearly identical. The title is The Sense of Hearing (see facing detail; public domain).