Except that early music doesn't necessarily stay symetrical--In point of fact, it was not customary to delineate measures until relatively recently. Also, having listened to the MIDI(not that I am an expert, mind you), I think that the melody is rendered with much too strident a beat--best to contact the person who made the MIDI and ask what the source material was and what it actually looked like. I think you will find, when you break open the file, that there is an e-mail address embedded there, as well as a website (I got jcclark@csupomona.edu), --of course, you may not feel any great need to try get academic about it--Still, the arrangement is copyrighted--