"Breves dies hominis" by either <a href="https://en.wikipedia.org/wiki/L%C3%A9onin" class="extiw" title="en:Léonin">Léonin</a> or <a href="https://en.wikipedia.org/wiki/P%C3%A9rotin" class="extiw" title="en:Pérotin">Pérotin</a>. Performed live by self.
<a class="external text" href="https://www.wikidata.org/wiki/Q297501">Leonin</a> or <a class="external text" href="https://www.wikidata.org/wiki/Q206275">Perotin</a>
<span class="int-own-work" lang="en">Own work</span>