Tongue Blocking Issue Moving Down The Scale

Assuming that the opening in your mouth is in the right corner of your mouth and on the right side of your tongue: 

When you move up the hole numbers, the harmonica is moving to the left in your mouth and:

• pushing the tongue to the left, which would enlarge the opening in your mouth
• pulling the right corner of your mouth to the left, which would reduce the size of the opening.

When you move down the hole numbers, the harmonica is moving to the right in your mouth and:

• pulling the tongue to the right, which would reduce the size of the opening in your mouth
• pushing the right corner of your mouth to the right, which would increase the size of the opening.

It's also possible that you're relaxing or enlarging the opening as you move from hole to hole and then re-establishing your embouchure when you land on the target hole; beginning players often do theis unconsciously.

Try this.

1. Instead of playing a scale, just play all blow notes, sliding from 4 to 5 to 6 to 7 on a single, uninterrupted breath. Try to arrive at each hole with no audible transition and arriving on a clean, isolated single note on each hole.
2. Now start at Blow 7 and slide back down to 6 to 5 to 4, again on a single breath.
3. Now try playing Draw 4 5 6 7 8 on a single inhaled breath.
4. Then slide back down Draw 8 7 6 5 4 on a single inhaled breath.

Working this exercise isolates the hole changes, without the complication of breath changes. If the moves down the hole numbers are still not clean (i.e., all notes are not isolated single notes), work on this. The main thing to go for is no change in the size and shape of your embouchure. This involves two main elements:

• Not changing your tongue or lip positions.
• Not pressing the harmonica hard against your lips and tongue, which can drag them out of configuration when you move the harmonica.

If you can make the moves above cleanly, then try it with the scale.

If the problem returns when you play the scale, pay attention to what happens when you change both btreath direction (blow/draw or draw'blow) and hole. You may be unconsciously changing your mouth opening.

 Hope this helps. let me know how it goes.

The V, or U-block as it's commonly known, is an embouchure used by some really great players, but for many essential techniques, tongue blocking is more versatile. Some folks use U-blocking for single notes, and switch to tongue blocking when they need it for specific techniques and effects.

I'm not sure what you mean by 11:00 and 1:00, but I'll try to explain some of the basics.

To directly answer your main question, though, most single-note tongue blocking is done with the hole played through an opening in the right corner of your mouth, with the tongue blocking the holes to the left. This lets you lift your tongue off to add lower pitched notes to the single note (assuming you're holding the harp right side up wtih Hole 1 on the left; some folks do hold it upside down, which is fine.) 

If your single note is on the left side of your tongue, you will sound *higher* notes when you lift it off. This is an interesting effect (I use it sometimes) but it is very rarely used; I'm not sure I've ever heard it on a blues record.

As to applying your tongue to the harp when tongue blocking, don't angle it to the right or left. Advance the tongue directly forward to touch the face of the harmonica. You can apply the tip directly to the holes, tuck the tip under the holes and press the broad surface of the tongue to the holes or even angle the tip up and use the underside of the tongue (I do the latter to block just one hole with the holes on either side open).