Rhythm is the flow of music. It's not just the order of the notes played, but the length they're held and the space in between them.

A-B-C is very different than A~~~------B-C~, for example, even if it's still the same three notes in the same order.

And that is clearly defined by writing down the notes. The length and the space between. That is the reason why we have the 1/1, 1/2, 1/4, … notes. On how those notes are connected and so on.

A note is a single instance of a sound by pitch and duration. A note does not include the space in between or the timing.

But then the space is much larger than 8^12 once you include all those variants - that’s the claim I’m responding to.

Well, he could mean that some notes are connected (where I think we all mean the 8 notes are of equal measure). So between every two consecutive notes you can add a line, multiplying the space by 2^7