If keeping the beat (whatever that is) were really the most important element in music I would never have persevered to become a musician.
As a young player dealing with notated music of other eras I simply could not keep a beat on the piano. (It was a problem I never had on the organ, interestingly.) When I was playing music written in my time, by Gershwin or Morton Gould, for example--music that corresponded to what I heard on a daily basis--there was no problem. So what is happening here?
I have grown to understand that the inherent tension between sonority and duration is so dramatic that it defies notation or theoretical explanation. An example: I play a chord in Beethoven that sounds absolutely wonderful. I love it and want it to last forever. But Beethoven specifies that I must let go of it, after a mere eighth-note duration. But why should I when that goes against all my instincts?
That is the drama I am talking about. It could be that the essence of rhythm in classical style is better conveyed by dealing with release than with attack.