[dlam]

I think it's clear to me that RPM is rhythm and the MPH is speed.
The pivot is the only true rotation part of the machine.
The arc and the hinge mechanism travel more or less in a straight line. The pivot regulates the rhythm because it's the true center and of it's rotatory nature.
I suppose one can listen/play a musical piece with same rhythm but different tempo.But it can not longer be a musical piece if there is tempo without rhythm.
No rhythm. No golf swing?