Patterns contained in a piece can be edited by opening the main pattern editor, clicking on the square icon in the list of patterns (next to the + and - buttons). You can use the regular tools and menus to edit the content of the pattern at will, just like you edit the main piece. Note that the changes you make automatically propagated to the pattern instances, as you make changes to the pattern's content. If you change the duration of the pattern by adding or moving sounds in it, the new duration is automatically recomputed at some time intervals. The pattern instances in the piece are adjusted proportionally to the ratio of the former duration of the pattern to the new duration. This resizing makes it convenient to create patterns that add delay or chorus effects to each sound instantiating this pattern.
Alternatively, you can edit a pattern and see its change propagated to all the instances of this pattern, by calling first Effects > Ungroup pattern on a single instance of the pattern. Then, edit the sounds that compose your pattern at will, and choose Effects > Make Pattern. Finally, use Effects > Replace with Pattern to replace all the instances of the old pattern with instances of the changed pattern.
In the registered version, the pattern editor (which resembles the composite waveform editor) editor provides some supplementary parameters:
Default pitch. This number represented the estimated pitch at which a pattern is tuned. This value is automatically computed. It needs not correspond to the actual pitch that is heard when playing the pattern, but this is of little relevance, as the pitch value is used relatively to the sound's actual pitch on the main score. One reason to edit this default pitch is to transpose all the sound instances of a corresponding pattern by a certain amount.
Reset pitch: recomputes the default pitch based on the lowest sound shape composing this pattern.
Recompute: forces recomputation of the total duration over which the pattern is defined. Normally, the recomputation is done automatically when you move sounds composing the pattern around, to encompass all those sounds and only them. Sometimes, however, you will want this recomputation to take place sooner, so that you can keep editing your pattern with an appropriate view.