Am i right in thinking that the guitar you refer to being played in 18th century was more akin to the Cittern than the modern day guitar? Interesting that it was used as an alternative to the flute. I'm actually wondering more about the modern guitar and, more specifically, the steel-strung acoustic guitar, which i don't think emerged until the late 19th century when luthiers such as Gibson, Martin and the Larson brothers began making them.

Jack, would you know if the guitar in the photo of Lady John Scott is a guitar like i have just described or is it a spanish guitar or english guitar etc.

Thanks a lot,
Mat