While HEX can use sampled sounds via the browser, it will sound much
better if you use an external MIDI software instrument, like a nice
guitar or piano. Mac users can use Garage Band for this purpose.
Windows users can use a free MIDI instrument like <a
 href="https://www.studiologic-music.com/products/numaplayer/"
 target="_blank">NumaPlayer</a>. There are also many
free piano&nbsp;VST plugins, but to use them with HEX you will need
to run a VST host so the plugin looks like a standalone app to Windows.
If you want to try this route, try <a
 href="https://plugins4free.com/plugin/2564/" target="_blank">Salamander
Piano</a> plus Tone2's <a
 href="https://www.tone2.com/nanohost.html" target="_blank">NanoHost</a>.
The help link in HEX's MIDI setup will tell you more about how to set
up the a MIDI loopback port, which you will need for any kind of
software instrument. <br>
<br>
This harmony explorer app was <i>vibe coded</i> with
Gemini Pro 2.5 in a couple afternoons, by someone who is neither a
developer nor a musician. Set your expectations accordingly.<br>
<br>
<b>Release Notes (Nov 13, 2025)</b><br>
<br>
First public release. <br>
<br>
Known Issues<br>
<ul>
  <li>When choosing a sampled instrument instead of your own MIDI
instrument, the first few notes/chords after a page load may not play
properly. For example, a chord may drop some notes. This clears up
after a few chords are played and should not reoccur until the page is
reloaded.&nbsp;
  </li>
  <li>Many YouTube example links in the Chord Progression Library
are broken.</li>
</ul>
Goals<br>
<ul>
  <li>Add a cursor to the chord progression editor, so additions
and deletions can be made from any point, not just at the end of the
sequence. </li>
  <li>Add a method for the user to save their own creations. This
would likely require the connection of a Google Drive account, as this
app is intended to run on a dumb web server, with all logic in the
browser.&nbsp;</li>
  <li>Put this hot mess on Github.</li>
</ul>