manual/include/fundamental-concepts.html

<p>Ardour's MIDI editing is based on two basic principles:</p>
<ol>
  <li>Editing should be done without having to enter a new window</li>
  <li>
    Editing should be able to carried out completely with the keyboard,
    or completely with the mouse, or with any combination of the two.
  </li>
</ol>
<p>
  Currently,  MIDI editing is primarily restricted to note data. Other
  kinds of data (controller events, sysex data) are present and can be
  added and deleted, but not actually edited.
</p>

<h2>Fundamentals of MIDI Editing in Ardour 3</h2>
<p>
  MIDI, just like audio, exists in <dfn>regions</dfn>. MIDI regions
  behave like audio regions: they can be moved, trimmed, copied (cloned),
  or deleted. Ardour allows either editing MIDI (or audio) regions, or MIDI
  region content (the notes), but never both at the same time. The
  <kbd>e</kbd> key (by default) toggles between <dfn>region level</dfn>
  and <dfn>note level</dfn> editing, as will double-clicking on a MIDI region.
</p>
<p class="note">
  One very important thing to note: editing note information in Ardour
  occurs in only a single region. There is no way currently to edit in note
  data for multiple regions at the same time, so for example you cannot select
  notes in several regions and then delete them all, nor can you copy-and-paste
  notes from one region to another. You can, of course, copy and paste the
  region(s), just as with audio.
</p>