Final answer:
A menu is not an instance, while image files, song files, and word processing documents are all examples of instances.
Step-by-step explanation:
The question asks to identify which option is not an instance. In computing and software terms, an instance typically refers to a specific realization or example of an object. Considering the options given, images, song files, and word processing documents can all be instances. They are individual realizations of more general concepts: an image file is an instance of a picture or graphic; a song file is an instance of a musical piece; a word processing document is an instance of text-based information or literature. Conversely, a menu is not typically an instance but a part of a graphical user interface or a list of options within a software application or system.