My original post, for the record!
Accordingly, I post a partial prior response to a similar posting:
["With all due respect to those who have posted, I have noticed that there is no specific mention regarding any method of "key attack." This references how one/pianist strikes a particular key or a set of keys.
1) I was taught, by my late teacher Robert Weaver, that one should rest their hands, with fingers "resting" on the keys, in a standard five finger position, at "Middle C" (and a corresponding octave below).
2) That also means you are sitting erect, not stiff, but relaxed at the keyboard, with a full but relaxed arm weight.
3) Then, practice playing (super slow!) 1-5 in a very soft staccato fashion with little or no movement in either hand (super still!).
4) After one has mastered this, the same modality should be effectuated with broken chords and dominant seventh and diminished arpeggios, accordingly."]
In terms of speed, if you are genuinely concerned with my prior discourse on that subject, please contact me by PM.
Thank you so much for your interest in this very important technique discussion.