I want to expound on my comments of a couple of months ago about most people not using enough mouthpiece pressure, which I’m sure raised a few eyebrows.  It’s certainly more complicated than just the amount of mouthpiece pressure a person uses in the upper register.  One of the challenges we face as brass players is to be able to consistently pick off entrances soft or loud in the upper register. There are many ways to go about this, some which are much more successful than others.  One of the most common methods is to set the embouchure for a lower note and push the upper lip against the upper rim of the mouthpiece and squeeze out a note.  I have found this to be an undependable way of making entrances in the high register.  Another method is to start the note from the diaphragm area, which replaces the tongue and squeezes the note out from the lower torso muscles.  Again this is an undependable way of making high entrances because it results in a substandard sound.  Then there is the pure pressure method where the mouthpiece is placed on the lips with no particular setting and the note is produced by pressure alone.  Usually this leads to many notes not speaking at all.  Another common method is the no pressure system, where other parts of the body take over the necessary firmness of the embouchure and again, notes are squeezed out from muscles other than the face.  There is also a tendency, and I have done this myself, to have a fear of embouchure collapse when playing high and loud.  This causes us to under set and use the upper lip/upper rim method to force out the note.  How much pressure is enough?  Hold your arm out and focus on how still you can keep your hand.  Hard huh?  Now lean your outstretched hand against a wall with just enough pressure to keep it absolutely still.  That’s the way you keep notes steady.  Also, there are basically two kinds of mouthpiece pressure which are useable in playing.  The first is when playing loud and high, bringing the mouthpiece closer to the face by a combination of the arm bringing the horn closer to the face and bringing the embouchure closer to the mouthpiece.  Then there is another more subtle way to use pressure to stabilize the embouchure for holding long notes at a soft dynamic.  That is by visualizing the horn as an unmovable object (like the wall) and leaning the embouchure against it to keep it completely still, therefore requiring only the monitoring of the air stream to hold a note perfectly steady.

The best way to develop a consistently dependable high register in my opinion is to set the corners of the embouchure with enough firmness that allows the player to blow across what feels like a horizontal plane, using the right amount of mouthpiece pressure required to keep the embouchure stable, and the right amount of air flow to balance that pressure and firmness of embouchure.  Think of the embouchure as an elevator which must travel to the correct floor, and that floor must be lined up evenly for the note to emerge unhindered. This will focus all of the firmness needed in the facial area and not in the torso area, which I believe to be the secret in developing a reliable upper register. EVERYTHING SHOULD HAPPEN FROM THE CHIN UP.  The angle at which the airstream emerges from the embouchure has alot to do with the type of sound a player produces.  Generally speaking, a player with a too dull type of sound should try to raise the angle of the air stream, and a player with a too bright type of sound should try to lower the angle of the air.  

When it comes to slurring in the high register the most common fault I’ve noticed is a tendency for the embouchure to arrive late to the desired note.  There is a natural inclination to get the slide or valve to the position before the air or embouchure, either of which will cause a miss.  Having the air arrive in time is not enough.  The embouchure needs to be set before the air and slide arrive to a slurred note in the upper register, something which is little understood.  It should feel like the embouchure is waiting at the correct setting for the air and slide to arrive.