mmcnabb wrote: ↑
Fri May 24, 2019 6:00 pm
It seems that if you simply pluck through the string and let the finger relax to its previous position, then its trajectory would pass directly back through the string in the opposite direction - i.e. a rasgueado stroke.. Thoughts?
My own view of ballistic RH style (playing with impulse force) is that each stroke ultimately consists of a brief flexion impulse followed by a brief extension impulse. The flexion impulse lauches the pluck while the extension impulse launches the return. In free stroke the flexion impulse is focused in the middle joint while the extension impulse focused in the knuckle joint; this ensures that pluck and return have different trajectories, so the finger doesn't hit the vibrating string on the return. In a rasgueado stroke, by contrast, both impulses are focused in the middle joint, which ensures that pluck and return have the same trajectory, so the finger hits the string in both directions. Further, in a rasgueado stroke both impulses have equal magnitudes whereas in free stroke the extension impulse, not being involved in sound production, has a far smaller magnitude. The sheer slightness of the extension force after the substantial flexion force creates the feel
of relaxation following the pluck. This, I think, is what it is about.
As a teacher I'd try to spare the student as much mechanical detail as possible. For free stroke I'd ask them to exert a strong flexion impulse on the middle joint then fully relax, and hope the rest will take care of itself. If it doesn't, i.e., the finger has difficulty clearing the vibrating string on the return, I'd ask them to exert a slight extension impulse on the knuckle joint right after the pluck, to correct the return trajectory.
Hope this helps clarifying the issue.