Lostinidlewonder and Arensky are both right, of course. I admit that the underlying conundrum of how much effort I should put into the technique of playing other people's music and how much into the peculiar expression of my own ideas, is one I have never resolved. Most jazz pianists and improvisers do not strive for universality of technique, preferring to concentrate on what they have to say personally. Those who do play classical, for example Jarrett, usually keep to those composers whose music makes technical demands most closely resembling their own strengths.
I too have been struck by the ease and fluency, the complete union of physical and creative means, which is exhibited in some of those old clips on youtube. Waller is a case in point. Sadly, few shots exist of his playing, but in those available, for example about a minute into Aint Misbehavin, the fluency and delicacy is impressive in such a big man, who was talking, joking, singing, and was probably drunk into the bargain. It is conjectured that Waller, who, it is known, played a lot of Bach and Rachmaninoff privately, made classical recordings which RCA suppressed for fear of altering his public image. What a pity if this is true.
Topic: Erroll Garner totally amazing technique.