manual/include/track-types.html

<p>
  Ardour offers three <dfn>track types</dfn> depending on the type of
  data they contain, and differentiates between three <dfn>track modes</dfn>,
  depending on their recording behaviour.
</p>

<h2>Track types</h2>
<p>
  An Ardour track can be of type <dfn>audio</dfn> or <dfn>MIDI</dfn>,
  depending on the <dfn>data</dfn> that the track will primarily record
  and play back. <em>However, either type of track can pass either
  type of data.</em> Hence, for example, one might have a MIDI track that
  contains an instrument plugin; such a track would record and play back
  MIDI data from disk but would produce audio, since the instrument plugin
  would turn MIDI data into audio data.
</p>
<p>
  Nevertheless, when adding tracks to a session, its content is typically
  known, and Ardour offers three choices:
</p>
<table class="dl">
  <tr><th>Audio</th>
  <td>An <dfn>Audio Track</dfn> is created with a user-specified number of
  inputs. The number of outputs is defined by the master bus channel count
  (for details see <a href="#channelconfiguration">Channel Configuration</a>
  below). This is the type of track to use when planning to work with
  existing or newly recorded audio.</td></tr>
  <tr><th>MIDI</th>
  <td>A <dfn>MIDI track</dfn> is created with a single MIDI input, and a
  single MIDI output. This is the type of track to use when planning to
  record and play back MIDI. There are several methods to enable playback
  of a MIDI track: add an instrument plugin to the track, connect the
  track to a software synthesizer, or connect it to external MIDI hardware.
  <p class="note">
    If an instrument plugin is added, the MIDI track outputs audio alongside
    MIDI data.
  </p></td></tr>
  <tr><th>Audio/MIDI</th>
  <td>There are a few notable plugins that can usefully accept both <dfn>Audio
  and MIDI</dfn> data (Reaktor is one, and various "auto-tune" like plugins
  are another). It can be tricky to configure this type of track manually,
  so Ardour allows to select this type specifically for use with such
  plugins. It is <em>not</em> generally the right choice when working normal
  MIDI tracks, and a dialog will warn of this.</td></tr>
</table>

<h2 id="trackmodes">Track Modes</h2>
<p>
  Audio tracks in Ardour have a <dfn>mode</dfn> which affects how they behave
  when recording:
</p>
<table class="dl">
  <tr><th>Normal</th>
  <td>Tracks in <dfn>normal mode</dfn> will record non-destructively&mdash;new
  data is written to new files, and when overdubbing, new regions will be
  layered on top of existing ones. This is the recommended mode for most
  workflows.
  </td></tr>
  <tr><th>Non-Layered</th>
  <td>Tracks using <dfn>non-layered mode</dfn> will record
  non-destructively&mdash;new data is written to new files, but when
  overdubbing, the existing regions are trimmed so that there are no overlaps.
  This does not affect the previously recorded audio data, and trimmed regions
  can be expanded again at will. Non-layered mode can be very useful for spoken
  word material, especially in combination with
  <a href="@@pushpull-trimming">push/pull trimming</a>.
  </td></tr>
  <tr><th>Tape</th>
  <td><dfn>Tape-mode</dfn> tracks do <strong>destructive</strong> recording:
  all data is recorded to a single file and if a section of
  existing data is overdub, the existing data is destroyed irrevocably&mdash;there is no
  undo. Fixed crossfades are added at every punch in and out point. This mode
  can be useful for certain kinds of re-recording workflows, but it not
  suggested for normal
  use.</td></tr>
</table>
<img class="right" src="/images/a3_nonlayered_example.png" alt="normal and non-layered overdubbing comparision"
/>
<p>
  The screenshot on the right shows the subtle difference between an overdub
  in <dfn>normal mode</dfn> (upper track) and one in <dfn>non-layered mode</dfn>
  (lower track). Both tracks were created using identical audio data.
</p>
<p>
  The upper track shows a new region which has been <dfn>layered on
  top</dfn> of the the existing (longer) region. It can be seen by the region
  name strips.
</p>
<p>
  The lower track has split the existing region in two, trimmed each new
  region to create space for the new overdub, and inserted the overdub region
  in between.
</p>

<h2 id="channelconfiguration">Channel Configuration</h2>
<p>
  Ardour tracks can have any number of inputs and any number of outputs, and the
  number of either can be changed at any time (subject to restrictions caused by
  any plugins in a track). However it is useful to not have to configure this sort
  of thing for the most common cases, and so the
  <a href="@@adding-tracks-busses-and-vcas">Add Tracks</a> dialog allows to
  select "Mono", "Stereo" and few other typical multichannel presets
</p>
<p>
  The name of the preset describes the number of <dfn>input channels</dfn>
  of the track or bus.
</p>
<p>
  If Ardour is configured to automatically connect new tracks and
  busses, the number of outputs will be determined by the number of
  inputs of the <dfn>master <a
  href="@@understanding-basic-concepts-and-terminology#busses">bus</a></dfn>,
  to which the track outputs will be connected.
</p>
<p>
  For example, with a two-channel master bus, a Mono track has one
  input and two outputs; a Stereo track has two inputs and two outputs.
</p>
<p class="note">
  If <kbd class="menu">Edit &gt; Preferences &gt; Audio
  &gt; Connection of Tracks and Busses</kbd> is set to <kbd
  class="menu">manual</kbd>, then tracks will be left disconnected by default
  and there will be as many outputs as there are inputs. It is up to the user to connect
  them as desired. This is not a particularly useful way to work unless something
  fairly unusual is done with signal routing and processing. It is almost always
  preferable to leave Ardour make connections automatically, even if some changes
  are manually done later.
</p>