Mr. Anonymous was less famous in the Baroque era than in the Renaissance. Partly as a consequence of the art of printing, names of the composers became known, because everyone was very proud of his or her name on the front page.
Nevertheless, I found some anonymous pieces from this era.
Click the title for playback and sheet music:
Here is a miniature Baroque suite that fits on two sheets of paper, composed by an anonymous composer that I could find nothing about. The Partita has the movements Prelude, Menuet, Gavotte, Sarabande, Gavotte and Gigue.
The Partita is in D minor. That implies a B sharp at times and an F on an awkward position. Yet it is worth the effort, there is quite some variation within the scope of two pages.
This is a fine example of a Baroque suite, written by an anonymous composer. The assumption is, that the Partita was composed around 1750. The movements are Intrada, Bourree, Double (de Bourree), Menuet, Gavotte, Double (de Gavotte) and Passepied.
At first sight, the complete suite looks a tough job, yet it is worth the effort. It is fun to play the Doubles with strong contrasts in comparison to their Bourree and Gavotte respectively.
This minuet by an anonymous composer originates from a collection from the Benedictine monastery Kremsmünster, Austria. This was the very first Baroque piece that I played as a beginner, having lessons with Thea van der Meer. At that time, I could not read a single note, so it took a while before I played them all on the correct place on the finger board.