It's not mine, and I'm not certain of the origin, but I think I saw the words "musicians" and "theater" in the Google preview when I checked the wording.
I've only seen it a handful of times in the wild - notably, a flight school wall - and every so often to close out blog entries on High-Speed, Low-Drag™ topics in (i.e.) aviation, search and rescue, emergency medicine, etc.
There's a few clever "practice" ones too that I can't seem to recall, other than: "Oops, guess that's why they call it practicing medicine!"