18:31 That's interesting. It's a Bajo Quinto made from the ground up, but what happened here was that back then they didn't have Bajo Quinto Tuners. So they just used Bajo Sexto Tuners & used only 10 of them that were needed.
I have a sexto I have to repair. Can't wait to watch this to help understand the instrument a little better. There's no brand name or markings at all so I know it's the real deal.