his compositions
... that Carl Nielsen selectively assigned an Opus number to only 44 of his compositions, running from Op. 1 to Op. 59?
... that <a href="./Carl_Nielsen" id="mwA_M" rel="mw:WikiLink" title="Carl Nielsen">Carl Nielsen</a> <i id="mwA_Q">(pictured)</i> selectively assigned an <a href="./Opus_number" id="mwA_U" rel="mw:WikiLink" title="Opus number">Opus number</a> to only 44 of <b id="mwA_Y"><a class="mw-redirect" href="./Carl_Nielsen_works" id="mwA_c" rel="mw:WikiLink" title="Carl Nielsen works">his compositions</a></b>, running from Op.<span id="mwA_g" typeof="mw:Entity"> </span>1 to Op.<span id="mwA_k" typeof="mw:Entity"> </span>59?