Rune's trumpet page, LIPS

Lip roles

The common belief is that the lower lip controls the tone height, while the upper lip does the vibrations. I think this is right for most traditional, downstream players with an 2/3 upper lip 1/3 lower lip mouthpiece placement. Some players even pin down the lower lip with the mouthpiece rim. With much upper lip in the mouthpiece, the tone quality will be more pleasant.

But for upstream players that usually plays with much more lower lip in the mouthpiece, the lower lip vibrates more. And because the lower lip is potentially stronger, the upper register will be easier accessible.

In the process of moving the jaw more forward, my lower lip started to vibrate much more after a couple of weeks. (It took some time because it was a bit stiff caused by the old way of playing.) This gave added sing to the tone, which became fuller.
When I started moving the jaw forward, other muscle groups are being used more. I really got to know that my muscles in the chin and the corner muscles were very weak.

Aperture

Observing the aperture while doing some buzzing on a visualizer or screw rim can be an interesting experience. Doing this in the mirror, I see that the aperture width varies with pitch. Only the lowest pitches open the aperture to the edges of the rim. Buzzing the higher ones, the aperture lies inside the rim and is not constricted by it.
All this might indicate that quite small rim sizes can be used for playing trumpet. I also guess that the size of the aperture depends on pitch alone, and not the individual.

The shape of the aperture varies with the degree of puckering, smiling and pinching. The most pleasant sound is obtained when the aperture is oval. Smiling and pinching flattens the aperture, while puckering rounds it.

There must be balance in the musculature for the aperture to stay the same shape over a wide range. Very often, the muscles that controls the pucker are not well developed.
The more muscle force that is required to play, the flatter the aperture gets. This limits our range, and also has the unpleasent result of a changing tone quality when ascending or descending.
Developing strength in the muscles that pucker (corners) requires special attention. Ordinary playing tend not to strengthen these muscles well. Personally, I find that pedals played for strength and lip buzzing, are the two most effective ways of strengthening this muscle group.

Closed lips principle

I think that the most effective use of the lips, will be getting the most buzz possible with the least amount of air used. This is obtained using the closed lips principle.

The lips should not be forced together, but held as close as possible without pinching. To be able to play with this setting, the lips must be supple. Usually, softening of the lips are required, so a more concentrated buzz point can be developed. More corner support and a little more pucker will help.
Playing pedal tones with closed lips can be of great help in developing a concentrated buzz point.

Closed lips results in a concentrated and brilliant tone quality, often preferred amongst commercial players. The tone quality might be too bright for players that like a dark sound.

Raphael Mendez talks about loosening the lips in great detail in his book. Jim Manley and Bill Carmichael preaches the importance of playing with closed lips.

Lip problems

Stiff lips

Most trumpet players will sometime in their career be plagued with stiff lips. If action is not taken, the trumpet player will eventually get so stiff that he hardly can make any sound.

A trumpet player with a stiff center will tend to open up the aperture. This is a very inefficient situation that demands use of more strength than necessary, cutting endurance and loss of the top register. Much embouchure motion is required causing loss of flexibility.

The recipe for the problem is lip fluttering and buzzing low and soft notes every time for warming up and warming down.

Soft lips

The lips can also get too soft. Especially if buzzing is overdone. It fill feel like the lips are sticking to the rim, impeding movement.

This condition can be confused with stiff lips, because the end result is the same, a too open aperture.

But in this cause, the open aperture is a result of excess rim friction. The only solution is to forget about it, and play the trumpet until the lips gets back to normal.

Playing in the red

By playing in the red, it is meant that the inner rim diameter is placed in the red of the lips.
The upper lip is the most fragile, severe damage can be done to it. If possible, the lower lip should also be kept out of the red. An active lower lip means a lot strength and endurance wise.

For some players with big lips, playing in the red is almost unavoidable. To solve the problem, lips can be rolled in, so the lips will fit inside normal rim sizes. Playing with closed lips will also help in getting out of the red.
If it still is impossible to play with all the red inside the mouthpiece, the important issue is that the rim is securely placed on the ring muscle and not on the muscle less red tissue.
It can be noticed that quite a few big lipped screamers play (or played) in the red.

I think that players with normal and thin lips should not play in the red. Such players have much weaker tissue, which will not withstand the abuse without being damaged.

Feedback

The Trumpeter's Handbook by Roger Sherman explains equipment feedback in an interesting way :
When the aperture gets feedback from the mouthpiece or the instrument, this feedback will close the aperture to some degree.
If one blows in the mouthpiece without buzzing and puts a finger over half the hole, the buzz will start. If the finger is removed it will stop.
Blowing on the mouthpiece without buzzing and inserting it in the instrument, the aperture will close up from the feedback and a sound will come out.

It seems like equipment feedback closes the aperture regardless of the embouchure that is used. The more the lips are rolled outwards, the more the feedback will close the aperture. Rolling the lips inwards, the feedback will also have an effect, although less in magnitude.

Doubling

Unfortunately, I have not been in the position to play a big instrument, such as the trombone or tuba. Every player I know of that doubles, have had real benefits from it. I think that what actually happens when doubling, is that the center of the lips gets softer. Also, playing a bigger rim, aperture control must be used. This trains this mechanism which is more difficult on smaller mouthpieces.

In my big band, we had a screamer that plays the baritone in a wind ensemble twice a week. He didn't have the opportunity to practice the trumpet, but he could still shake the walls with his double C's.

Some other prominent doublers are : Maynard, James Morrison.
If you have the opportunity to hear Morrison, do it. He is great!

More about doubling on Nick Drozdoffs page : Myths about doubling