--- a/midi/specification.html	Wed May 23 12:23:33 2012 +0300
+++ b/midi/specification.html	Wed May 23 13:35:23 2012 +0300
@@ -290,6 +290,45 @@
 
     <section>
       <h2><a>MIDIInputDevice</a> Interface</h2>
+
+      <p>
+        Whenever the MIDI device corresponding the
+        <code><a>MIDIInputDevice</a></code> sends a MIDI message, the UA MUST
+        run the following steps:
+      </p>
+
+      <ol>
+        <li>
+          <p>
+            Let <code>device</code> be the <code><a>MIDIInputDevice</a></code>.
+          </p>
+        </li>
+
+        <li>
+          <p>
+            Let <code>messages</code> be a newly constructed
+            <code>sequence&lt;<a>MIDIMessage</a>&gt;</code> corresponding the
+            MIDI messages the device sent.
+          </p>
+        </li>
+
+        <li>
+          <p>
+            Let <code>event</code> be a newly constructed
+            <code><a>MIDIEvent</a></code>, with the <code>MIDIMessages</code>
+            attribute set to <code>messages</code>.
+          </p>
+        </li>
+
+        <li>
+          <p>
+            Fire an event named <code><a
+            href="#event-midiinputdevice-midimessage">midimessage</a></code>
+            at the object, using the <code>event</code> as the event object.
+          </p>
+        </li>
+      </ol>
+
       <dl title="[NoInterfaceObject]
                  interface MIDIInputDevice implements EventTarget"
           class="idl">
@@ -311,6 +350,12 @@
         <dt class="no-docs">[TreatNonCallableAsNull] attribute
                             Function? onmidimessage</dt>
         <dd>
+          <p>
+            This event handler, of type <code><a href=
+            "#event-midiinputdevice-midimessage"></a></code>, MUST be
+            supported by all objects implementing
+            <code><a>MIDIInputDevice</a></code> interface.
+          </p>
         </dd>
       </dl>
       </section>
@@ -384,6 +429,22 @@
           </p>
         </dd>
       </dl>
+
+      <section>
+        <h3><a>MIDIEvent</a> Interface</h3>
+        
+        <dl title="[NoInterfaceObject]
+                   interface MIDIEvent : Event"
+            class="idl">
+          <dt>readonly attribute sequence&lt;<a>MIDIMessage</a>&gt; MIDIMessages</dt>
+          <dd>
+            <p>
+              A sequence of <code><a>MIDIMessage</a></code>s associated
+              with the event.
+            </p>
+          </dd>
+        </dl>
+      </section>
     </section>
   </body>
 </html>