That was musical skill and, in particular, the skill of performing composed polyphony.
Given the rise of polyphony in the period, this allowed the expansion of both music and the musicians' economic, social and professional status.
In short, canons at the unison are children's 'rounds' by which they could sing their first imitative polyphony.
The last two sections are both centred around the relation between notation and polyphony and the systems of modal and mensural notation.
Especially adept at polyphony, he was noted for learned, at times complex, but often accessible pieces, particularly church music.
None of the contributions concerns either polyphony or secular music-making; the focus is on the history of plainchant and liturgy.
A polyphony thus develops, which becomes richer as the new reference points overtake the accumulated delayed voices.
In general, polyphony and newly composed pieces were restricted to the elite.
