When I finally got together with Rostropovich as a student, he was very focused, almost entirely focused on the music itself, on what the composer had in mind and what he knew about the composer. Many of the works that I played for him had in fact been composed and written for him; he was often the first performer of these works, having known the composers personally.
I don't think too much about the past when I am actually playing, I prefer to concentrate on the present. The performance of a piece, no matter how long ago or where it was written, is always a new production, something that comes alive in the present. And it doesn't matter if the piece was written two or three hundred years ago if it is alive in us.
Our interpretations through the years and generations have always changed, but the emotions, ideas, and the thoughts of the composers are still with us, and these are the premise of the music. The time factor has little to do with it because, after all, it is about human feeling, the Universe and who we are as people.