I don't play the baroque lute myself, and don't have any interest in maintaining or propagating any "written in stone" statements about playing styles, string materials, hip or not hip, nails, temperaments or whatever. On the contrary, I'm for a "free for all" in this respect. On the other hand, I'm a member on this list, because there is such a vast knowledge to be found among its members when it comes to anything plucked and especially the search for answers concerning how it was done originally. In this context, I'm quite certain, that the thumb-in, thumb-out discussions when it comes to baroque lute playing have been numerous here throughout the years. Not wanting to open any can of worms, it still seems logical, that due to the greater width on a BL, thumb out looks like the right procedure for this instrument. I think Dowland even had a say. Runs are of course another matter, and one certainly doesn't exclude the other.
Always happy for answers G. -- To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
