So to come up with a time signature that allows us to logically organize the periodic beats in traditional music, we start by figuring out where the beat is, then how beats are grouped.
We can think of this as perceiving two different durational levels.
The beat is primary, usually somewhere around 60 to 130 beats per minute.
Then there is the measure which is obviously a longer duration - 2, 3, 4 or so times the duration of the beat.
But there is another durational level that we’ve already heard in the Beethoven. There are durations that are shorter than the beat.
