How to get "Drop D" to stay in tune

ors Thanks for bringing this remarkable performance to our collective attention! I am aware of the existence of this repertoire, but have not given it the attention it obviously deserves. I'm surprised there is so little interest in it - even among Russians, apparently. It's great to have a performer of Marten Falk's calibre bringing it back to life!

ors The best solution for the music of Weiss (short of acquiring a lute) is Michael Thames' 13 string 'Dresden' guitar. Probably not something you'll find at your local guitar dealer's, though! (So why not - if this is repertoire you love - just 'bite the bullet' and take up the lute!)

David Krupka Michael Thames's guitars are great, but he is on the other side of the Big Blue Pond for me!

I realize that a 13-course lute would be very interesting to explore Weiss + Bach's music, but then, I would need to start taking lessons to adjust my technique (thumb-in vs thumb-out, nails vs no nails, suppressing unfretted basses, reading different types of tablature notations eventually, etc.) and I am no Brandon Acker (he is amazing by the way, if you don't know him already)!

And talk about (re-)tuning issues: on a 13 string course lute, that would be 27 strings to tune -- I would have to re-start from the first once I reach the 27th as the strings adjust to out-of-the-case humidity, ha ha ha!

More seriously, and I know that for purists among lutenists the following is a bit of a "sacrilege" to even mention, but Luito Forte would be a choice if I were to go that route: a modern single-string/course lute (a "cursed lute"?!) with geared-pegs that stay put (though they have the olden-look), with many choices in terms of number of courses and tuning, and that you can play thumb-out with nails as a CG: 

https://liuto-forte.de/en/welcome/models-overview/

Maybe a used Liuto Forte would be good investment to explore, if I ever see one on Reverb or the like. But then again, one needs to have the time to invest in the study of the 13-stringed instrument and the music ... this when this poor chap barely has 30-60 mins/day to play his 6-string CG!

ors The transition to lute is probably less difficult than you imagine, but not, to be sure, without its challenges. Tuning is indeed a big nuisance, although a 13-course lute has 'only' 24 individual strings, not 27! (I know, big difference ...) And, just as you suggest, fine-tuning after the first go-through is (in my experience) generally required, even without issues of humidity. (Although we do get some of that here in the Great Lakes region.) On the plus side, the lower courses (from eight down) are rarely stopped with the left hand, so they maintain their pitch fairly well over time. Right-hand technique for the baroque lute is not too different than guitar technique - 'thumb-in' applies mostly to repertoire for the six-course lute. Just how to approach music for the later 'renaissance' lute is matter of considerable debate, but by the eighteenth century, it's all 'thumb-out'.. Another contentious issue concerns the use of nails, with some modern players (like Brandon Acker) arguing in their favour. The 'old guard' (players like Nigel North and Paul O'dette) remain (by and large) 'flesh-only' purists. (I know which team I'd rather be on!) The biggest hurdle to competence on the baroque lute is learning to navigate the large number of courses needing to be plucked by the thumb - it's very easy to lose track of where one is. (And the occasional glance down isn't too useful either - all those strings can be a real 'trompe l'oiel'!) But for the fretting hand, the baroque lute is far easier than either its renaissance cousin or the modern guitar. (This has to do with both the D minor tuning system, and the fact that so many notes are available as open strings.) The music of Weiss is much less demanding on the lute than it is on the guitar, for example. Bach (whose music probably wasn't intended for the lute) is another matter though! My advice is - if you want to play Bach, stick with the guitar! I know of the Liuto-forte, and even considered one myself in the past, but a lutenist friend of mine talked me out of it. In the end, I think of it as a sort of half-measure for the not-really-committed. It's like ordering a lite-beer - if you don't drink the real stuff, why go to the pub in the first place? An alternative to the Liuto-forte is a normal lute, single strung, which seems to be an increasingly popular option, even among some professionals. See, for example, this, from Scottish musician Rob MacKillop: https://www.youtube.com/watch?v=R08K-HaBdYk

David Krupka Thank you for detailed response. Rob MacKillop's video is very interesting and convincing regarding using a regular lute but with single-coursed strings (I love Rob's videos ... and I can see myself moving to Scotland just to get a bit of that accent!) If Le Luth Doré restarts the production here in France again as indicated, I might be tempted to order a lute from them, since they proposed quality instruments that were very reasonably priced. The real bottleneck is the free time that remains after work and family ... So for the moment, the 6-string guitar music will do more than plenty ... Thanks again for the great discussion across the Atlantic. A lot of food for thought, as they say. 

ors Time is always an issue! I circulate through my various instruments, rarely trying to juggle more than one at a time. It means I don't develop real mastery of any, but I quite enjoy exploring their different repertoires, even if in the end I don't play any of it particularly well. But that's okay - I didn't play guitar all that well, either, even when it was the focus of my musical interest.