I'm trying to learn a Japanese instrument called the Kokyuu (here, on the right), but I'm not sure if I should press the strings all the way against the neck, I was wondering if someone could help me think this one out? I can't tell what characteristic the notes in the linked video have, but I do know that I can make notes just by touching the string at a certain position- but I believe that creates overtones which might not be part of the traditional playing style. I was wondering if anyone could provide insight as to whether or not it would make sense to press the string all the way down, and also whether or not the linked video looks/sounds like the player is pressing the strings all the way down.
I did some research on this and found some very strong indicators that the string is indeed pressed against the fingerboard.
The most convincing point is offered in this book on composing for japanese instruments. The chapter on the Kokyu starts at p.112 and likens many techniqual aspects of playing to the Shamisen, where the strings do indeed touch the fingerboard.
p.121 even has a paragraph on the technique of 'kokiotoshi', that goes a bit more into left hand technique and includes strong hints that the strings are indeed pressed down against the fingerboard.