doc.tom: who is traditional? If they are alive now, they must have come in contact with "untraditional" music. Ditto if they are dead and wrote down their tunes, with or without additional parts. See all those threads about WhatIsFolk.

Would Oswald von Wolkenstein qualify, a genuine counterpointist and certainly neither a man of the Church nor an academic?

Anyway: if you choose to write new music other than in unison, you should try to do it in a way that satisfies today's ears. On the other hand, be careful when changing live traditions.