I already posted about that topic about a year and a half ago.
I’m hitting a wall trying to master fast and tremolo strumming.
My reference points are the examples of great strumming proficieny in the Andy Wood acoustic interviews and the Olli Soikkelli and Joscho Stephan interviews. Granted, those are elite players in the 1% of technical excellence.
I find fast/tremolo strumming to be a degree of difficulty above tremolo picking single notes. In the latter, I have an anchor point close to the pick (the side of the palm). In the former, the anchor point is much higher (high area of the forearm close to the elbow) and each stroke’s length is much bigger.
Those videos have been great in that my strumming, espeicially my upstroke, used to really suck. Now it is fast and fluid enough to tackle many pop songs with good tone. But even after a ton of practice over months, anything beyond medium fast still remains impossible.
I have run out of ideas as to how to approach the problem. One thing I could try is practice a single notes tremolo while keeping my wrist floating as opposed to anchored at the palm. I am aware that fewer guitarists are interested in rhythm guitar but I still think it would be amazing ot have a dedicated chapter in the Primer - to me, the difficulty would justify it.