Harmonica mouth-organ

Harmonica or mouthorgan for Groove Tongue or U block technique or tongue technique

Groove Tongue

This article is taken from http://www.angelfire.com/music/HarpOn/

This embouchure is also known as U block or tongue roll.
You can play single notes by placing the tip of your tongue underneath the played note, in other words using a U-block. Your lips usually enclose three holes. The played note is usually centered and the outside notes blocked with the left and right edges of the tongue, which form a U shaped groove. The tongue tip is on the lower coverplate or just under the reedplate edge under the hole(s) to be played. Push the relaxed tongue forward so the inside of the cheeks "u" it up to block the side holes. The U shape sort of naturally happens when the tongue is pushed forward slightly (and perhaps upward), because the tip stays anchored below the played note. As with tongue blocking, the key is relaxation and light pressure on the harp.

The following quotes are from a variety of emails and responses by John Thaden, I've tried my best to keep them in context and true to his meaning. They were sourced from Harp-L archives

"the reason I [John Thaden] prefer that name (or Leo Diamond's term, groove tongue) to tongue roll, is because in fact you don't have to have the genetic gift of tongue-rolling to be able to do it, at least the looser roll, or U version that I use. It is the inside of the cheeks that support the tongue's U shape, as it is pushed slightly forward. I've taught two people U-blocking who cannot roll their tongues at all."

"As with tongue-blocking, the teeth are opened enough so the harp fits between them. The lips cover anywhere from 3-5 holes. The cheeks generally are not permitted to 'pooch' out and in as you breath, and in fact as you'll see, it is the inside of your cheeks that actually help the tongue form the 'U' shape. The tip of the tongue is below the mouthpiece, under the hole or holes to be played. Try some variations: Sometimes I have the tip just beneath the mouthpiece or exposed reedplate edge, sometimes further down onto the lower cover plate. Sometimes the tip is between the lower front teeth and the harp, sometimes inside the teeth. See what works for you.

"Push the relaxed tongue slightly forward. Because it basically has no place to go and because the tip is 'trapped' under the mouthpiece, the edges of the tongue will contact the inside of the cheeks, be forced up into a shallow U, and block the outer holes. That's all there is to it. The end result you should strive for is a very relaxed embouchure with very light pressure of the tongue on the harp, so you can easily move on the harp, and do tongue slaps and chording.

"If the above description doesn't get you there, then try this modification: With the harp and mouth positioned as described, tip the harp so the mouthpiece rolls down against the top surface of the tongue and all the holes are blocked. (This may force your teeth slightly further apart, but don't worry about it -- this is only a learning exercise.) Now roll the harp back slightly and notice which hole sounds first. It may well be the center one. If so, you are on your way to U-blocking. You are really there when you can do it with the harp level, both side-to-side and front-to-back, which is how I hold it."

"...it's advantages as being speed and accuracy, low fatigue factor, rock-steady bends, and identical harp position to tongue-blocking, resulting in both a tone more similar to tongue blocking than puckering, and quick, easy switching to tongue-blocked corners and octaves."

"... The key to both U-block and tongue-block bending is controlling the size and position of the opening (aperture) dividing the cavity of your mouth/upper throat from the rest of your airway. In other words, the action happens back in the throat. Exactly where depends on the note being bent and the tone you want, but concentrate on those areas where you would form the 'k' sound, the hard 'g' sound, and where you would clear your throat or cough. A combination of aperture control and airflow control is what forms the bend; the tongue is therefore perfectly free to maintain the embouchure, do slaps and chords, articulate notes, or -- with very subtle changes in shape and position --fine-tune the bend and embellish it with vibrato and effects. The word 'solid' somehow describes bends done in this way.

"... Articulation is the way one note is divided from the next. The available methods while U-blocking include the glottal 'minicough' championed by Douglas Tate, the consonant sounds 'g' and 'k' and 'L', 'modified' consonants 'd' and 't' (but using the center instead of the tip of the tongue against the upper hard palate), the badly-named 'bite' technique (where the upper lip leaves the harp to break the air seal), and of course changing air direction, and moving from hole to hole."

"[with] u-blocking ... you can do switches. With it and standard tongue-blocking, you now have three positions among which to switch (more actually because the u-block can itself be swept across several holes). Specifically, the left, center, right legato move ... requires no motion of the harp in my mouth when the center hole is open in a u-block. If I play it with a pucker (spit), I have to pull the harp out of my mouth a little from the tongue-block, which is too slow."