anchor.diff:  	<h1>HACC</h1>
       <h2>Human-Aided Computer Composition</h2>
   	<div class="row-fluid">
  +        <section id="about">
  +            <div class="row">
  +                <div class="col-md-6 col-md-offset-3">
  +                    <!-- http://getbootstrap.com/javascript/#collapse-example-accordion -->
  +                    <div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
  +                      <div class="panel panel-default">
  +                        <div class="panel-heading" role="tab" id="headingOne">
  +                          <h4 class="panel-title">
  +                            <a data-toggle="collapse" data-parent="#accordion" href="#whatsthis" aria-expanded="false" aria-controls="whatsthis">
  +                              What's This?
  +                            </a>
  +                          </h4>
  +                        </div>
  +                        <div id="whatsthis" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingOne">
  +                          <div class="panel-body">
  +                            Human-Aided Computer Composition (HACC) was an exploratory project I started in 2010 to see whether computers could compose music effectively. Over the course of 21 months, the programs I wrote (in <a href="http://www.wolfram.com/mathematica/">Mathematica</a>) were able to produce sixty-second violin duets, string quartets, and fiddle tunes. Below is the result of rewriting my fiddle tune code in Javascript. Select a key by clicking on the appropriate radio button, click "Generate Fiddle Tune", and (thanks in part to the <a href="http://mudcu.be/midi-js/">Midi.js</a> library) my program will start playing a newly-composed Irish reel.
  +                            <br><br>
  +                            I plan to port my violin duet and string quartet code to Javascript soon. Until then, have fun making reels!
  +                          </div>
  +                        </div>
  +                      </div>
  +                    </div>
  +                </div>
  +            </div>
  +        </section>
   		<section id="music">
  -            <div class="col-md-6 col-md-offset-3 center">
  -    			<button class="btn btn-primary" onclick="random_fiddle_tune()">Generate Fiddle Tune</button>
  +            <div class="col-md-6 col-md-offset-3">
  +                <div class="form-group">
  +                  <div class="col-sm-2 col-sm-offset-5 center">
  +                    <label class="control-label">Key</label>
  +                  </div>
  +                  <br>
  +                  <div class="col-sm-12">
  +                    <div class="row">
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="0">C Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="1">C# Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="2">D Major
  +                        </label>
  +                      </div>
  +                    </div>
  +                    <div class="row">
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="3">D# Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="4">E Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="5">F Major
  +                        </label>
  +                      </div>
  +                    </div>
  +                    <div class="row">
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="6">F# Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="7">G Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="8">G# Major
  +                        </label>
  +                      </div>
  +                    </div>
  +                    <div class="row">
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="9">A Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="10">A# Major
  +                        </label>
  +                      </div>
  +                      <div class="col-sm-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="11">B Major
  +                        </label>
  +                      </div>
  +                    </div>
  +                    <div class="row">
  +                      <div class="col-sm-4 col-sm-offset-4">
  +                        <label class="radio-inline">
  +                          <input type="radio" name="key_choice" value="-1" checked>Random
  +                        </label>
  +                      </div>
  +                    </div>
  +                  </div>
  +                </div>
  +                <div class="col-md-6 col-md-offset-3 center">
  +                  <br>
  +    			  <button class="btn btn-primary" onclick="random_fiddle_tune()">Generate Fiddle Tune</button>
  +                </div>
  +                <!-- <button class="btn btn-primary" onclick="MIDI.Player.pause()">Pause</button> -->
               </div>
   		</section>
               <div class="col-md-6 col-md-offset-3">
  
positive.code: 
      // function for generating a random fiddle tune in a random key
      var random_fiddle_tune = function() {
          // pick a key randomly
          var key = Math.floor(Math.random()*12);
          // generate the tune
          var tune = fiddletune(key);
          // play the tune at 75 beats per minute
  
negative.code:             // console.log("start and end times for " + tune[0][note] + ": " + (0.75*note) + " and " + (0.75*(note+1)));
              MIDI.noteOn(0, tune[0][note] + 60, 127, (60/tempo)*tune[1][note][0] + offset);
              MIDI.noteOff(0, tune[0][note] + 60, (60/tempo)*tune[1][note][1] + offset);
          }
      };
      </script>