title: Music21 and MuseScore can't display .png in jupyter notebook
body: <p>I run this very simple set of commands to display some sheet music:</p>
  <pre><code>import music21
  music21.environment.set(&quot;musescoreDirectPNGPath&quot;, &quot;/snap/bin/musescore.mscore&quot;)
  bwv295 = music21.corpus.parse('bach/bwv295')
  bwv295.show()
  </code></pre>
  <p>I am getting the error:
  <code>SubConverterFileIOException: No png file for /tmp/music21/tmpwh3jnppk.png (such as /tmp/music21/tmpwh3jnppk-1.png) was found.  The conversion to png failed</code></p>
  <p>I have made sure to install libpng. I also checked the debug of jupyter and it is saying a couple things:</p>
  <ul>
  <li><code>cannot load canberra-gtk-module (I sudo apt-get installed libcanberra-gtk-module)</code></li>
  <li><code>unable to load printer plugin &quot;qtubuntu-print&quot;</code></li>
  <li><code>File &quot;/tmp/music21/tmpwh3jnppk.xml&quot; not found.</code></li>
  </ul>
  <p><a href="https://i.stack.imgur.com/uoKUO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uoKUO.png" alt="screenshot" /></a></p>
  <p>But, my temp directory definitely contains this file with populated information</p>
  <p>Any thoughts?</p>