Here is the definition as described by Dr. Reinhardt:
The lips and mouthpiece "as one unit" must move vertically on "the track of the inner embouchure (the teeth for trumpet - the teeth and gums for trombone) and whether or not this movement is to be in an upward or downward direction to ascend or descend is strictly based upon the performer's particular physical type.
The name "pivot" was used in connection with brass playing and the sport of golf. Dr. Reinhardt was an avid amateur golfer and took lessons from Ben Hogan at a very early age. Much to his regret, this term made him both famous and infamous. Notwithstanding his bold nature and ability to infuriate the brass community with his criticsm of "tradition" when it tread on the toes of Mother Nature, the term "pivot" was much maligned, mis-interpreted and definitely used improperly from "flag waving" by some and downright "denial" that it even existed at all in one's playing.
How a word can cause so much consternation and uproar is not so uncommon. I remember that when Sister Kenney used the word "spasm" in dealing with Polio that the medical profession refused to accept her work and ridiculed her for such a "non-scientific word" and all too often one becomes "an enemy for a word". I have used a term in my own writings that is more French, in keeping with the use of French in brass terms such as "embouchure". I played with "finesse demarche" for a time, where the movement (demarche) is one of "finessing" the embouchure to achieve what Doc was talking about. Recently, I have been liking the word "inflection", where the ever so slight movement (eventually)is nothing more than a "rising or falling(lowering)" to one degree or another. Perhaps a "finessing inflection" might eventually fit the bill.
Well, "A rose by any other name will still smell as sweet", so call it what you like, I suppose, but know that it does work, is necessary to ascend and descend, and EVERYONE does it.
If one reading this doesn't have The Encyclopedia of The Pivot System, let me quote from it now:
"...a PIVOT is the physical means by which a performer may constantly maintain the all-essential line-up of his lips with his teeth, so that the required lip vibraions for the production of sound are not hampered or impeded in any particular part of his range".
and again "...the PIVOT pulls or pushes the performer's lips into the path of the air column, so that the air column will cause the lips to vibrate over the entire range of the instrument". [Remember that it is the air COLUMN that flows from the lungs, over the tongue and to the lips, and it is the air STREAM that is propelled into the mouthpiece cup]
Since we all are teachers, whether ultimately "our own teacher", teaching others privately or teaching the youth in a school setting such as Middle School, High School or College level, I will be gearing FixYourBrass to include teachers and performers. My posts will have various "topics" (Range, for example), with information for development and maintaining these categories as well as problems that may arise. The posts may be followed by my own "comments" and as to solutions to these problems watch for follow-up posts. So please add your own comments as to create a dialogue regarding said posts as well as any "personal problems" that I can help with. Looking forward to this exchange.