The other films in the series are all just as fascinating. The Bass one interested me especially as I had built a true Baroque type instrument as late as 1996. It was thicknesses [in the front and back] to carry gut strings rather than being more heavily made to carry steel.
This apparent oddness was the result of owning an "old English Bass" of the type normal from GF Handel's time onward in England. Three strings tuned off the bottom, A, D, G. This is one of tuning schemes discussed in the film. Mine was London Circa 1780, and was a top class instrument of the modern large size which by then was normal, and an even longer string length than is "standard" now: 44 inches rather than 42. It was carefully converted to carry four gut strings with the modern tuning of E, A, D, G, but I often used to use the bottom string tuned to D for Baroque music. This is the tuning the lady has on her instrument [about a hundred years older than mine] and yes, that bottom string had a huge sound! Brilliant in the music of Haydn for example, though not needed for JS Bach, and it was easy enough to play quieter than its potential allowed.
Sadly that instrument was worth so much that I could not afford to insure it, and perhaps Lady Fate proves yet again what a horror she can be, the instrument was damaged to the extent of a £3000 repair while left unattended at a concert hall. So I had it repaired and sold it, but very much below its real worth. I though it was worth about £14,00 back in the early 1990s. In fact it was worth six figures, which I did not know. A big mistake selling it for four figures! But I commissioned the new bass, and it was a wonderful instrument ...
With best wishes from George