Lets say that you are a scientist, a physicist and mathematician. You are a genius and have just invented a new technology that could revolutionise the music industry… How would you pitch the idea to the directors and business team of your company, they are not scientists, but hold the power to release the funds you need to finish off the work?
Well if you were Alan Blumlein and had just developed stereo technology at EMI’s Central Research Laboratories, you’d create a large scale model. His model showed how one needle in a specially cut groove on a record could give out two signals simultaneously resulting in a more stereophonic sound. Here is a short video of that model in action. Notice the difference in readings between the two dials.
Sound Of The Hound 
What an utterly fabulous device, now for Quadraphonic Sound!
Sadly most buyers would have been happy cranking the handle
on thier re-enterant tone chamber gramophone, with its tin of
steel needles in 1931. Alas so few electric radio gramophones
were sold that year, the great man never lived to see his device
taken up in practice.