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"You don't need to throw away a harmonica because of a blown reed."

Part 1
See Part 2: How to replace a reed on a diatonic harmonica.

Reeds fracture with use. You don't need to throw away the harmonica because of a blown reed. Just like broken guitar strings can be replaced, so can harmonica reeds. In fact, you can change a harmonica reed in the same amount of time it takes to change a guitar string (maybe less!)

Reeds don't usually break off, they just drop out of tune because of microscopic fractures. If you play hard you will blow out reeds faster. Plink a fractured reed over and over and you will hear the pitch drop until the reed just stops moving - and eventually falls off - because the fracture grows to the point where it's not microscopic anymore.

Harmonica reed replacement is simple but it's not always easy. Replacing harmonica reeds is a bit of a paradox.

The chicken or the egg? Where do you start?

The first thing you need to do to a reed that has been freshly replaced is adjust its curvature so that it plays well. This is much more involved than just gapping. Re-shaping reeds takes some time and practice to learn. As part of the learning process, you will probably damage some reeds and they will have to be replaced.

That's why replacing reeds is an advanced skill.

To guarantee the new reed sounds right, there are a few things to consider:

1- Fastening a reed onto a reed plate can do some funny things to its shape. You need to be able to check and correct the shape of a reed to have success 100 per cent of the time. See this reed work reference.

2- Taking a reed off and putting one back on may also bend the reed plate if you are not careful. It's important to try not to bend the plate as you work. You must check for flatness once you are done and straighten a crooked reed plate.

3- Don't forget about tuning. The new reed will probably be out of tune - sometimes factory-new reed are out by as much as 50 cents! You will need to tune it.

Most harmonicas use rivets to secure the reeds to the plate because it's very cost-effective to mass-produce them that way. But there are other - better - ways of fastening a reed to the plate. There is nothing special about using a rivet.

A reed that's attached to the plate with a screw will not sound any different than a reed attached with a rivet. What's important is that the reed is secure, straight and centered and has a proper shape/curve.

Using a screw will allow you to get the reed perfectly positioned and won't warp the reed plate. You can guarantee success 100 per cent of the time.

Suzuki reeds are welded onto the plate. They don't use rivets. You don't need to buy a welding torch. The reeds can be removed easily by twisting the rivet pad just like rotating a reed with a reed wrench. To fasten the new reed, you drill a hole into the new reed and into the plate and secure the replacement reed with a screw.

Where do you start? Just jump on in!

See Part 2: How to replace a reed on a diatonic harmonica for the procedure.

Part 2

I learned how to make combs from friends with over 100 cumulative years of machinist experience! This is my low-tech, high-precision method of making exquisite harmonica combs. You can use this method to flatten the stock comb on your harmonica to make it play better.

The diatonic harmonica is made of solid pieces that must fit together in a way that is airtight. Mass-produced harmonicas often are not airtight and can be improved with a few minutes work.

This process is usually a little faster but the using a camera slows things down a bit.

Use this process on Hohner Bamboo Laminate (Crossover and Thunderbird) combs or the stock Suzuki Manji comb. You can also flatten a comb made of Corian or any other solid-surface material using this method. Be careful not to drop Corian combs - they shatter.

Wooden combs will swell. To flatten wooden combs like the Seydel 1847 or Marine Band Deluxe/1896 combs, I recommend you seal the surface after you flatten. Check for flatness after you seal, too.

Do not use this method on recessed-type harmonicas like the Special 20, Session or HarpMaster harmonicas. Those harmonicas use a different design concept. Checking and adjusting flatness on those combs requires a different strategy. Straightening and flattening the reed plates will make the best of the thin plastic combs in those models and will offer you great results. For perfectly flat reed plates, use The F Tool™.

This is the comb tool™. I meticulously flatten the top edge. *Only* the top edge is flat - we will be using that edge as a reference.

My comb tool is a working copy of a high-precision straight-edge (some call this a machinist square) precise to .000025" per 6" (25 millionths of an inch). The original stays in a drawer! If I were to use it on every comb I make, it would eventually wear out.

You can get a set of my comb tools here: Comb Tool™.

We will be measuring flatness along the left-to-right axis.

We will be measuring flatness along the up-and-down axis. That means in between every tine.

We will be sanding the comb surface. Tape a piece of 220 grit sandpaper to a flat surface. I use a granite surface plate but any flat surface will do. Don't obsess about the flatness of your working surface. The only thing you need to make your comb perfectly flat is a flat reference.

Place the comb tool over the comb to distribute the weight of your fingers evenly over the surface of the comb.

Move the comb around in circles in both directions until it feels smooth. This usually takes a few seconds. Flip it over and do the other side.

Place the reference along the surface of the comb and hold it up to the light. Hold it only on one side so that you can see how the other side behaves.

Switch sides. this gives us a good clue as to where the comb is bowed and where to flatten.

Put the comb down on the flat sandpaper and apply finger pressure where you want to flatten. Drag the comb along the sandpaper. Check flatness and repeat until it's flat.

Rotate the comb so that you are checking the tips. One tine is leaky here. Flatten the other tines to fix this.

Check in between each tine.

Switch your grip from side to side to reveal where the curve is.

Apply finger pressure and drag the comb to fix.

This is flat.

You can use the tool to apply even pressure to a portion of the comb - just like you used your finger. If the comb was unflat in this area, I would apply pressure like this:

Use this technique on both sides to fix a curve that is concave downward.

In summary, the hard part is measuring flatness. Once you can tell where the comb is not flat, it's easy to fix.

Extra tips!

Here are some extra tips on using my comb tool:

Comb tool extra tips page

Warning: This blog post contains physics.

Here is an excellent demonstration of what happens when we bend notes. See what happens at the 3:00 minute mark.

When he finds the volume of the tube that is resonant to the frequency of the tuning fork, the sound increases. The frequency of the tuning fork stays constant though. Harmonica reeds are special because they can vibrate at different frequencies. We can make them vibrate faster or slower.

We apply “bending energy” by changing the size of the oral cavity just like professor Sumner Miller changed the size of the resonance chamber (cardboard tubes). Resonance is what applies kinetic energy to the reeds to make them vibrate at the desired frequency. If you want the reeds to vibrate slower, you open up your oral cavity to lower the resonance frequency. The reeds follow. It’s as simple as that.

Hopefully an understanding of what happens as you play a bent note can help you learn how to execute the technique.

Knowing the physics behind it allows you to free yourself from overthinking things. Don’t worry too much about tongue position, “U”-shape, “W”-shape, “G”-spot.... Just make an air pocket in your mouth and when you find the right size, the note will bend. Figure out what works for you to be able to re-create an air pocket of exactly the correct size every time you want to play that note.

It’s a little bit of a moving target when you consider that as you inhale, the tissues of your oral cavity will suck in and the air pocket will shrink. Conversely, the air pocket will grow when you blow bend because of the positive pressure. But with a little practice, your mouth will figure out how to keep the size of the air pocket constant despite these opposing forces.

Your ears play a big role in this. But the interaction between your voice, your ears and the shape of your oral cavity is automatic (or “autonomic”) so no instructions are required - other than to mention to make sure you can hear yourself play!

Overbends are just like regular bends!

Overbends are a little more complicated because we need both reeds (blow and draw) in the system to respond to the same resonance in different ways. One reed needs to stop moving while the other one needs to vibrate at the correct pitch. The trick is to get the reed that is standing still to stay still even though we are applying airflow to the system.

Sometimes out-of-the-box harps are set up to allow this to happen. Sometimes, they are set up to inhibit this. It’s the luck of the draw. It’s a common misconception than you need to practice overbends for years before you can become good enough to play them. The truth is that overbends require breath control, resonance control and a harp that is set up to cooperate.

It’s likely that you can learn to use overbends musically in a matter of weeks with the proper harp and some dedicated practice. You don’t need to build muscle over several years like a bodybuilder. You simply need to learn fine motor control.

I really enjoy watching professor Sumner Miller. Here is another video from the good professor where he describes the phenomenon of beating. Again, watch starting at the 3:00 minute mark:

Hearing the beating is a very important part of how to tune a harmonica.

Embossing decrease the space between the reed and the edges of the slot. With higher tolerances can come better performance - the harmonica responds better and plays louder.

The thing about embossing is that so much can go wrong. Fixing the damage can take more time than it takes to do the actual work of embossing the slots.

So how to you "walk the line" to get maximum benefit without creating problems for yourself?

Some folks advocate special tools. Some use a light table. Others use a microscope - sometimes.

All those things can work well. But every method has its disadvantages.

For example, a fast-acting tool can overshoot the mark causing you to work against yourself. A light table only shows you two dimensions and as the reed passes through the slot in three dimensions, you can be left confused as to what you are seeing. A microscope can be overkill - you may not even need one if you have good eyesight. You certainly don't need to use magnification to do most of the work - if anything, you would want to shorten your view of the slot instead of zooming into one segment. But if you are over 40 years of age, using some form of magnification is probably good idea.

Let me share a secret with you: You can get top-level results using simple methods that don't rely on fancy technology.

How?

I'm not telling you. I don't make a habit of keeping secrets, but this is something I have never shared before in public.

I am happy to show folks the basics of how to tweak harmonicas and I have a strong preference for some methods, but there are may ways to get a task done. You don't need to know this secret to do a great job. This method's advantage is that it makes things easier and saves lots of time if you do it correctly.

Again, I'm not going to tell you what it is. I will, however, give you a clue.

Here it is. Print it out. (It's a way of looking at embossing.)

Contact me if you think you have it figured out. I'll let you know whether you are hot or cold. I'll add the most interesting responses to this page as they come in.

Good luck and don't hesitate to contact me!

2014/11/24 - Stephen C. described the way he holds the reed plate to "get a pretty good sense of what's going on in the space between the reed and the plate" and he's very close to what I describe!

2014/12/25 - Jaime G. wrote about "aligning tip edge with edge under rivet (to emboss) with a secure and efficient method."

EDIT: The mystery is over! My explanation can be found here!