A good example of non-image CC0 use is this set of recordings of Bach’s Goldberg Variations, which can be downloaded for any use: http://www.opengoldbergvariations.org/

As an example of CC0 images and their unrestricted use, use the images below for anything you want, without attribution. None were produced by mts.org and all are readily and freely available online. (click on an image to download the full-resolution file)

A mic picking up the sound from a guitar amp.

 

CC0 license found at https://creativecommons.org/publicdomain/zero/1.0/