Alypius
...that the sole surviving portion of the work of 4th-century musical writer Alypius is the chief source of modern knowledge of Greek musical notation?
...that the sole surviving portion of the work of 4th-century musical writer <b id="mwIw"><a class="mw-redirect" href="./Alypius_(music_writer)" id="mwJA" rel="mw:WikiLink" title="Alypius (music writer)">Alypius</a></b> is the chief source of modern knowledge of <a href="./Ancient_Greece" id="mwJQ" rel="mw:WikiLink" title="Ancient Greece">Greek</a> <a href="./Musical_notation" id="mwJg" rel="mw:WikiLink" title="Musical notation">musical notation</a>?