- Edited
Just to discuss one point Molly mentions in the first video. She says we've all had the experience of playing a piece at some level and then coming back to it a significant amount of time, like a year or more later, and thinking it's much easier than before. Then she says the improvement seems like it's more than what would happen simply because our general skills improved over that year. I don't see how anyone could measure that with any kind of scientific accuracy because there's no way of knowing how much easier the piece seemed due to the break we took from it versus our general improvement in pianistic skill.
I think what Molly said later on in the video is certainly reasonable and not at all surprising. I'm talking about the part where she compared spaced practicing to doing all the practice in one day. It seems perfectly reasonable that the longer one practices, especially if one takes no breaks at all, The more difficult it is to concentrate. But this is not the same thing as saying that after a certain amount of time in a given day, especially if one takes a break of several hours, the practicing is of no benefit. A much more reasonable statement seems something like after a certain amount of hours on a given day, the practicing becomes less productive which is not the same thing as saying it has no benefit.