It is possible that it was due to an ephemeral state brought on by listening to an hour of the other stuff. But:

I could tap my foot because the first beat of many measures was emphasized, and notes tended to have only a few lengths, which were integer multiples or divisions of one typical length, which in turn was an integer division of a measure. And I did tap my foot because the piano is more forgiving to "let's mess with octaves" moments, and the piece involved things like harmony and phrasing. There may even have been a cadence in there somewhere.