Many thanks to SWLing Post contributor, John, who writes:

The video below started with a curious investigation of a mysterious button found on 1980/90 era cassette recorders…. just to end up as being essential knowledge that we probably never had back on the day during our listening sessions.

I think the blog readers will love the most recent video from VWestlife:

Click here to view on YouTube.

Thank you for sharing, John!