I'm around grade 10 level.
Thomas Mark.
Mark's assumption that the the bones will support without tension is erroneous. The second doctored pic shows what happens if you try to put a key down without tension - the joints just break in.
As he says in the caption - 'the arch...can be the basis of playing without tension'. There is no such thing. Without tension during key depression your joints collapse (ultimately you fall off the piano stool).
I had never heard of Thomas Mark. I went to google him and I could only find "comedian and political activist". Thomas CARSON Mark. Interesting. A Taubmann offspring.Anyway, you're right, it's impossible to play without tension. It's how to RELEASE the tension immediately after playing the key that's the secret.
The best technique I have ever found is Ernest Hutcheson's book - Piano Technique. It really must be shown by a teacher and demonstrated to understand what he is saying. But it boils down every piano technique one will ever need to play anything in the piano literture in all in less than a few dozen pages. Most people are looking for technical books like Czerny, Hannon etc. But if you are really looking for a true book on piano technique, Ernest Hucheson's is tops. It is so simple and yet so straight forward it is amazing to realize how basic playing the piano really is. It takes hours to polish every aspect of technique - actually a life time. FYI he gave up his career as a concert pianist to start a little school called Julliard!
Words words...He is talking about allignment of the bones, which is the most important aspect of playing with a precise and focused movement.Tension is usually referred to the unnecessary and detrimental tensing of the muscles, as what happens when one continues to press into the keys long after it would have any effect.As birba states, the release is extremely important.
How could reading a book help someone play better?
I've read several posts on this forum by you that have resulted in improvements in my playing.Reading allows us to make use of other peoples experience to guide our own development.I don't think anyone would claim to be able to play better without playing, but there are certainlymore and less efficient ways of spending your practice time.