Claude Gordon introduced me to this technique which he called "K Tongue Modified. He said Herbert L. Clarke taught him this. Before I studied with Claude, I had always tongued with the VERY tip of my tongue releasing the air after touching the upper teeth and /or gums.
Claude assigned me the switch to "K Tongue Modified" when I first began studying with him at a crossroads in my life. I had just had my braces removed and could barely play above the staff. What I could play in the staff was uncomfortable. This was after approximately seven years of braces.
His teaching on the tongue involved two concepts, namely the tongue position and the tongue level. Claude advocated the articulation technique passed on to him by Herbert L. Clarke, one which seemed to lie dormant in Clarke's Characteristic Studies text after Clarke's death.3 The technique which Claude referred to as "K Tongue Modified" involves leaving the very tip of the tongue behind the lower front teeth and producing the "T" of the single tongue release with the front of the tongue.4 By front of the tongue I mean the area of the tongue between the very tip and the center of the tongue. Note: this is a very subjective matter. In some players this area may seem more forward and in others farther back. When mastered, this technique allows more efficient articulation, a more confident range and increased playing accuracy. After utilizing K Tongue Modified as your "normal" single tongue, the tongue soon easily moves between the specific level or shape required for each note and there is no need to switch from one embouchure setting to another from low to high range. In Claude's words, the player "will learn to feel every note." ( This paragraph is from my article link "The Teaching Philosophy of Claude Gordon" at my homepage listed below.)
It took me about a year of intensive practice (at least four hours per day) to feel confident and sound good using this technique.
For those of you who want to give it a try, do the following:
Leave the very tip of your tongue at the floor of your mouth just behind your lower front teeth and use the part of your tongue between the very center and the very tip to produce the "T" of the single tongue release from behind the upper front teeth. This is discussed by Herbert L. Clarke in his Characteristic studies text (pub.-C.Fischer-02281) on page 5, paragraph 7. With time and proper practice, this technique will make your tonguing, along with everything else, more efficient. I recommend starting with very simple low register single tonguing exercises in Arbans. Advance slow. Don't be in a hurry. At first , don't try to use it at gigs until your comfortable and confident with it.
Incidentally, Claude had taught that this "K Tongue Modified" technique should be used as your single tongue always in every register. He did not advocate using it interchangably with other single tonguing methods. He may not have said this in lessons to every individual student, but he did state this at his Brass Camps.
My analysis of the advantage of this technique is as follows. The tip of the tongue has to be out of the way of the air stream. In the lower registers, our awareness of this is not as easily discernable. However, as we go higher we will quickly become aware of this truth. The single tonguing technique of releasing the VERY tip from behind the upper teeth and upper gumbs becomes inefficient in the upper range because the VERY tip of the tongue has to get out of the way as the tongue forms the "EEE" syllable necessary to produce those notes. Of course, these syllables vary for each different note - they are not all just "EEE." "K Tongue Modified" is more efficient because the VERY tip always stays down; thus, it eliminates an unnecessary movement of the tongue.