Accepts NoteProcessors: yes
A soundObject pointing to a soundObject in the soundObject library. The content of the soundObject is not editable except by editing the soundObject in the library to which the instance is pointing to. If editing the soundObject in the library, all instances that point to that soundObject will be changed.
When clicking on an Instance object to edit it, the soundObject from the library will show its editor instead in the soundObject edit area but it will be clearly marked that the user is currently editing a library soundObject and not an individual soundObject.
The instance object is very useful if your work entails using many variations of single source of material; you could take a soundObject, put it into the library, then make 10 instances of it, adding noteProcessors to 'transpose' it, or get the 'retrograde of it', etc. and then perhaps later, if you decided you wanted to change the initial material, you'd only have to edit it once within the library, maintaining all of the transformations and relationships that were add via noteProcessors. You could also later change your mind and decide that you want to not have an instance there, so you could convert it to a generic score (a rt-click on the instance object and a menu click a way) and then be able to work with the source material again.