Drones and polyphony

My last post discussed a little the idea of adding a drone to a monophonic piece as an effective way to enhance an instrumental performance. It illustrates a more general idea - if you are going to borrow from the vocal repertoire (and as a medieval instrumentalist, you are going to quickly run out of repertoire unless you do) then it is useful, perhaps essential, to think beyond just playing the notes in the vocal score on your instrument. Rather, you need to investigate what your instrument can bring to this tune. Many good musicians do this instinctively but it is useful (especially for those of us who aren't 'instinctive' musicians) to think about it consciously as well.

I should thank a workshop with the fantastic lutenist Crawford Young for making this point explicit (and Chris for reminding me of it). Young complained of students presenting him with a 'note perfect' instrumental rendition of an Ars Nova motet - his comment was "what is the point?". An instrumental version of a vocal piece should not just be a pale reflection of what would be better sung, presenting the notes without the words. It should use the song as the starting point for something else.

But to get back to drones. Clearly if a polyphonic vocal piece is played with at least one drone instrument (such as bagpipe, hurdy-gurdy or (arguably) medieval fiddle) on one of the parts, then a drone will be added to the polyphonic texture. A repertoire we often explore in such a way is the medieval conductus: technically, sacred music but not 'liturgical' in the sense that it is not an essential part of the mass. We have found many examples of two-part conductus that sound great in a two bagpipe performance. In taking this music as a jumping off point for an enjoyable instrumental performance, are we doing something inherently modern, or could this be defended as plausible historical practice?