-<h2>Stretch</h2>
-
-<p>FIXME. Optional. What happens when disabled? Won’t match the current timeline
-tempo: START THE SECTION WITH THIS: ARDOUR ALWAYS MATCHES CURRENT SESSION
-TEMPO, SO TEMPO RAMPS WILL WORK FOR CLIPS</p>
+<h2>Stretching</h2>
+
+<p>
+ When you load an audio clip into a trigger slot, Ardour applies some
+ heuristics to estimate its temo in beats per minute. If neither the file
+ name nor the metadata specify it, Ardour will use
+ <a href="https://github.com/breakfastquay/minibpm">minibpm</a> to analyze
+ the file assuming it has a fixed tempo.
+</p>
+
+<p>
+ After estimating the tempo, Ardour will enable stretching for the clip
+ to make it match session's bpm at any given time. This means that should
+ session's tempo change over time (in either ramped or constant mode),
+ Ardour will re-stretch all audio clips to accomodate for that.
+</p>
+
+<p>
+ Disabling stretching when original clip's tempo doesn't match that of the
+ session will most of the times make the clip audibly go out of sync with
+ the beat.
+</p>