Balance, Half-Halt, Forwardness, Rhythm

And there will be many more......terms which are tossed about with flippant meanings that do not make sense to me sometimes. They are the lions & tigers & bears of riding which haunt me into the night. I need not strive to re-invent dressage but to understand it. On first observation these terms are not terribly obscure, but if I think about them for a while my head starts to spin. In order to describe how to develop feel through 'energetics' I will need to convey my own working definition of some things.
I'll start with 'balance'. I need to think of balance qualitatively. I cannot bring myself to say, "this horse is balanced" or "that horse is not balanced". To me a horse is balanced if he is standing on all 4 feet. He is not balanced if he is flat out on the ground! I can only comfortably talk about balance by saying phrases such as "that horse is well balanced" or "this horse is poorly balanced" or "let's improve the balance" or "optimal balance" or "bring him into a better(or new) balance" or "change the balance(thinking qualitatively)" or even "shift the balance".
I can sum up my difficulty with the term 'half-halt' by recalling what Francois LeMaire says about the term. If a half-halt is to be used to re-balance a horse we are in a lot of trouble if we keep needing to use it so frequently! I feel more comfortable describing targeted, specifically designed 'holds', 'retards', or 'shifts'. The dynamics of a moving horse are way too complex to throw a blanket term like 'half-halt' at.
Moving along to the term 'forwardness' or 'forward'. I just sighed when typing it!! Loosely, I would guess one wants the horse to move in a 'plus' or 'positive' direction, i.e. forward. What if you want to step backward? The whole issue for me is cleared up if I can just describe the term like this: the horse needs to be poised(or ready and willing) to move when asked. The degree with which he responds is his 'sparkiness' to my request. If he MOVES, I am satisfied! If he moves sluggishly, then he needs to be 'sensitized' to my request not be made to go more forward!
'Rhythm' is my next problem term. Rhythm is from the Latin 'rhythmus' meaning 'to flow'. So rhythmic might mean 'flowing'. It is also an ordered recurrent alteration of strong and weak elements in the flow of sound(Webster). Additionally, it is defined as the aspect of music comprising all the elements(as accent, meter and tempo) that relate to forward movement(Webster) and a characteristic rhythmic pattern(walk, trot, canter, gallop) and movement marked by the regular recurrence or natural flow of related elements(Webster).
Rhythm is a term rich in meaning but to develop feel in riding we need to be more specific in the way we use the term. We will not be able to understand 'energy flow' in a qualititative and quantitative sense unless we break this term down for clarity purposes. I will refer to rhythm as the metered beat----walk being 4-beat, trot 2-beat, canter 3(or4)-beat. We can further describe the regularity of those beats in terms of how evenly the footsteps touch the ground. The tempo is the speed of the beat of those footsteps and not the speed of the horse(I'll just call that fast or slow or somewhere in between). Tempo is characterized by the regularity of longitudinal flow of energy. And cadence is the expressiveness or emotion of the beat and is characterized by the vertical lift of the leg and vertical flow of the energy.
So the beats of the hooves are strung together in a regular rhythm of longitudinal and vertical flow which can be shaped into expressive dance.