Odo of ArezzoOdo of Arezzo or Abbot Oddo was a medieval monk who worked in Arezzo, active as composer and music theorist.Life and careerLittle is known about his life, except that he was an Abbot in Arezzo, working under Bishop Donatus of Arezzo. Odo composed a tonary with a discussion of modes, which survives in twenty manuscripts, four of which contain attributions to Odo. In several of the manuscripts a prologue ascribed in three out of six to Odo is entitled "Formulas quas vobis".