Over blowing is a technique for playing a wind instrument to produce a different pitch by forcing the air stream. A standard note is disturbed and one of the overtones of the note dominates. This is usually intentionally done and the resulting note is flat but can be “bent up” to attain the correct pitch.
Over blowing requires two simultaneous actions:
1. The direct reed should be silenced.
2. The opposite reed should make the sound.
Perform this by exerting strong back pressure in the mouth, throat and lungs. Correct shaping of the lips and the use of facial muscles are important when blowing directly into the mouthpiece of the harmonica.
How to Produce the Notes
Over blow and over draw allow you to produce all the notes not available in a diatonic harmonica. It is the same as bending; if the right reeds are adjusted as close as possible to the reed plates, there’s even no need to blow or draw with extra effort.
Adjusting the reeds is easy. Here’s how:
1. Remove the cover plates.
2. The outside of the lower reed plate contains the draw reeds. Push in with your finger nail and push back out by using a tiny screw driver or similar.
3. The blow reeds are on the inside of the upper reed plate. Reach for them and push, to place them closer to the plate; push them from the top to put them back.
These are the simplest things you can do with the reeds to have an easy over blow and over draw.
Now that you’re all set for over blowing, your first exercise is blow bending 8 blow; the bending should be very smooth at easy volume, up and down; there should be no space between the changes of pitch. Do 8 blow bends, from E to Eb.
Follow this with 6 blow (G) and do the same exercise on this hole. If your harmonica reeds are set close to the plates you will produce a higher note – Bb, a minor 3rd higher than G. Practice will get you good at this. You can bend Bb very low, to almost A, and up to B or C if the reeds are set very close to the plates. This works on 1, 4, 5 and 6 over blow. You can also over blow 2 and 3 blow to produce AB from OB and C from 3 OB.
Over blowing the first hole is different. You can make it easy by blowing 1, drawing 1, and then blow again to get an Eb. This is when your plates are set very near to the plates.
The over blow and over draw technique, mainly used by professional and advanced harmonica players, allows the entire chromatic scale to be played on a diatonic harmonica.
Unless you can perform all blow and draw bends smoothly, you shouldn’t try to do over blowing and over drawing. But all players should learn all the notes you get on all the bends, since this will be very useful in later playing.
