Is something missing?

One of my favourite British medieval music groups is the Dufay Collective. They were formed in 1987, by which time the 'a cappella' movement was well entrenched in Britain. As a primarily instrumental group it is not surprising that they focussed in their earliest recordings and concert programmes on performing that part of the repertoire which no-one (as far as I know!) disputes is instrumental - the estampies, instampittas, salterellos and so on. I just looked back at their CD notes to see whether any comment relevant to the 'a cappella' debate was made, and found that they lamented (like many others have done) that, as medieval instrumental music was mostly an oral and improvised tradition, the large majority of it is lost to us.

I think this is in one sense true: for example, there were probably many more dance tunes existing than those that were written down and have survived; and probably also approaches to performance (such as instrumentation, ornamentation and improvisation) that were not captured even where there is musical notation.

However, in another sense I am not so sure. Is it likely there were whole categories of instrumental music that existed but of which there is no record at all? Complete performance styles that we can never begin to reconstruct, however speculatively? And is the surviving vocal music not some clue to what instrumental polyphony - if it existed - might have been?