Kent, I was referring to his slow
practice demonstration, not the actual performance. Specifically, the portion 0:36 - 0:46 of the video. That's where he is plucking in ballistic play-relax mode with no sympathetic or opposed motion between fingers. Of course, as the speed increases the opposed and sympathetic instances you mention start to happen naturally.
The controversy in guitar pedagogy is how the phenomena observed at high speed should be accounted for during slow practice. Your video represents the sympathetic and opposed motion schools, cf. Berg, where any observed opposition or sympathy between fingers at high speed is deliberately ingrained by slow practice. Here's a summary of yours and Berg's tremolo practice schemes:
- Kent: flex p as am extend; hold; flex a, then flex m as i extends; hold; flex i as p extends; hold. Repeat.
- Berg: flex p as i extends; hold; flex a, then flex m, then flex i as pma extend; hold. Repeat.
Nothing wrong with any of these, of course. Just note that a finger held back, no matter how briefly, means the flexion action was not a mere
impulse and hence not ballistic. The hold intervals also mean there's never complete relaxation between strokes, as fingers are held back by some sort of holding tension, obviously. At high speed the intervals become very brief, even vanish, so that might or might not be a concern - I really don't know. Anyway here's the ballistic play-relax counterpart:
- Flex p and release immediately; flex a and release immediately; flex m and release immediately; flex i and release immediately. Repeat.
That's the slow
practice scheme I've been advocating throughout this thread and, I believe, demonstrated by Grisha in above mentioned 10 seconds portion of his video.