3 title: Equivalent Region Selection
7 <a href="/working-with-tracks/track-and-bus-groups/">Track Groups</a> have
8 a property titled <kbd class="option">Select</kbd> which, if enabled, cause
9 Ardour to propagate a region selection in one track of a group to the
10 <dfn>equivalent regions</dfn> of the other tracks in that group.
13 For example, let's assume you have used multiple microphones to record a
14 drum kit to multiple tracks. You have created a track group, added all the
15 drum tracks, enabled the group and enabled the Select property for the group.
16 When you select a region in one of the drum tracks, Ardour will select the
17 corresponding region in every other drum track, which in turn means that a
18 subsequent edit operation will affect all the drum tracks together.
21 <h2>How Ardour Decides Which Regions are "Equivalent"</h2>
23 Regions in different tracks are considered to be equivalent for the purposes
24 of sharing <dfn>selection</dfn> if they satisfy <em>all</em> the following criteria:
27 <li>Each region starts at the <dfn>same offset</dfn> within its source file,</li>
28 <li>each region is located at the <dfn>same position</dfn> on the timeline, and</li>
29 <li>each region has the <dfn>same length</dfn>.</li>
32 <h2>Overlap Equivalence</h2>
34 Sometimes, the rules outlined above are too strict to get Ardour to do what you
35 want. Regions may have been trimmed to slightly different lengths, or positioned
36 slightly differently, and this will cause Ardour to not select regions in other
40 <kbd class="option">Edit > Preferences > Editor > Use overlap equivalency for
41 regions</kbd>. With this option enabled, regions in different tracks will be
42 considered equivalent for the purposes of selection if they
43 <dfn>overlap</dfn>. This is much more flexible and will cover almost all of the
44 cases that the fixed rules above might make cumbersome.