Bach's Brandenburg concerto No. 3 (BWV 1048) doesn't have a slow movement. In the place where you would normally expect to find one, what's written out is just two chords. And in most modern performances, those chords get a perfunctory embellishment, a quick bit of a cadenza, and on we go. That's the shape in which the piece now sits in the classical canon, so nobody expects more than that.
