A harmonica won't "break" or sound wrong if you tune it a little differently than how it came from the factory. Harmonicas are said to conform to a certain temperament but most off-the-shelf harmonicas are not tuned precisely enough for the temperament to matter all that much anyway.
These days, if any chords are in harmony, it's usually limited to the bottom end of the instrument.
Before the 1960s, harmonicas were in much better tune because it seems that making a perfectly-tuned instrument was the primary focus at the factory. (Little did they know the same things they were doing to the instrument to help make the chords play well also helped make it easy to bend notes!) By making today's harmonicas play with harder breath and try to last longer, we've moved away from factory-made instruments that are in perfect tune.
Putting that aside, imagine that you do indeed get an instrument that is tuned with a lot of accuracy from the factory. What does that mean?
What is temperament?
Equal Temperament is a configuration where the pitches of all notes are divided up equally. In this configuration, chords don't sound in harmony. Tuning your harp to this configuration doesn't really require a lot of precision.
7-limit Just Intonation is a configuration where notes are slightly off-pitch to make the major chord of the scale play in perfect harmony. This configuration requires the most precision because each reed needs to resonate at an exact frequency to produce the strongest harmony.
Compromise tuning is anything in the middle, including "19-limit Just Intonation". Chords can be in tune and the notes can still sound fine when played alone. There are a few different "recipes" for Compromise tuning however there is not one best way to compromise between the two extremes.
Are octaves in tune? Compromise-tuned harmonicas are supposed to provide smooth octaves, but they often fall short. Most Equal Temperament harmonicas don't even try. What if you play octaves but don't play major chords? (Example: Playing in the style of William Clarke requires lots of octaves but hardly any chords.) You'd be very happy with Equal Temperament along with in-tune octaves which is less work than tuning for chords and octaves.
The tuning of some Equal Temperament configured harmonicas is so imprecise that some of the notes are farther out of tune than if configured for strong sounding chords.
The conclusion is: Your playing style may not align with one particular temperament. There's no need to conform to any particular configuration. You can tune a harmonica any way you like. Spend time working on the elements you need and save time by not worrying about the rest.
What should I use instead of temperament?
Decide which chords, octaves / intervals and single notes you need to be in tune.
- Do you need chords to be in tune? Which ones? Who says you can't tune half the harp for chords and the other half for single notes?
- Do you need octaves to be in tune? Do you prefer them wet*?
- Do you need the intervals of the Fifths and Thirds to be in harmony? Don't worry about any intervals other than octave, thirds and fifths.
- Lastly, does tuning for major chord harmony make the thirds sound too flat when played as single notes to your ear? If so, choose between the chord or the single note.
(*) Wetness is when an octave beats intentionally. Example: Tremolo harmonicas have two identical reeds playing the same pitch but slightly off-tune from the factory. On a 10-hole diatonic harmonica, tuning the reeds to be in perfect tune is ideal. You can hit the octave dry and if you want some wetness, you can phase out the pitch with your embouchure. You probably can't take a wet octave back in tune using your embouchure though.
I've created The Tuning Card to help you tune a harmonica freestyle - without necessarily using temperament. The Tuning Card helps you tune what you need.
Lay the plate (or the assembled harmonica) on the Tuning card. Use the colors to help you map out which reed you need to adjust.
Anyone who knows me will tell you that I do not advocate tuning "by the numbers." You won't end up with chords or octaves in tune if you simply play each note into a tuner and adjust the pitch. The pitch of a single reed played on a harmonica is not stable - it's influenced by our embouchure, our breath force and a few other factors.
Pick the method that meets your requirements:
Simple: If you never play chords or octaves, accuracy is not required. Use Equal Temperament. It's the easiest configuration. Simply use a tuner to tune all the notes to an offset of zero on your tuner. This is how most budget/inexpensive harmonicas are tuned. You can expect the accuracy of each note to be about + or - 6 cents.
Intermediate: If you like chords and octaves but are not skilled at tuning, tune only the elements you need. Tune the chords on the low end of the harmonica. Tune the rest for either smooth octaves or Equal Temperament. Chords and octaves can sound fine when tuned with an accuracy of + or - 2 cents.
Advanced: Perfect harmony gives your chords more power. Build a chord using dynamic breath for extra precision. Double check each note with the fifths and thirds. Use the octaves to tune the other chords and use their thirds and fifths to "square" - double or even triple check each reed for maximum precision. This process takes more time, skill and attention to detail. It requires accuracy and notes should be accurate to within a fraction of a cent.
Most people - even those with perfect pitch - can't pick up on 13 cents difference in absolute pitch. But relative pitch - when two notes are played together - is much more obvious to everybody, even those not gifted with perfect pitch.
The Tuning Card helps you through the process of tuning using relative values instead of absolute ones.
Reedwork is the work we do to make the shape of the reed such that it passes through the slot in the best possible way. The reed is curved at rest and will straighten out at the exact moment is travels through the slot.
Reedword is very precise work. It takes time.
All the time and effort to do reed work is wasted if the slots are not straight or level.
This is a reed at rest:
This is the reed the moment it travels through the slot. It's well set up and the most of the reed passes through the slot at the exact same time:
Framework is the work we do to make the slot perfectly straight and level. The slot is simply the rectangular hole in the reed plate.
If the reed plate or comb is curved front-to-back, that will mean that the slots will be curved too. The reed doesn't stand a chance of passing through perfectly under these conditions:
Not to mention this can also cause an air leak which will make the harp feel stiff.
Likewise, if the reed plate or comb is warped or bumpy left-to-right, one side of the slot will be higher than the other - again the reed will never pass through the slot optimally.
When I upgrade a harmonica's comb, the goal is to provide a foundation for the framework. If the comb is defective, you will never get the harp to provide a wide dynamic range or deliver its maximum tone.
This is an example of a comb that is bright and shiny on the surface but it lacks the fundamental qualities we really need. It's made of aluminium. I have never found an aluminium comb that meets my standards.
Its tines are very thin and don't provide a lot of surface contact.
But most importantly, it's bowed front-to-back. I measured flatness. This thing leaks air and has rotten tone. The tone is bright but thin.
I'm using my flatness tool™ as a reference. The light you see between the tool and the comb is where it's bowed.
Here is what the comb look like after being properly flattened:
It can be a challenge to hold the blow plate and draw plate together onto the comb and play a single note (or an interval) without affecting the pitch with your embouchure. The draw plate is easy because the reeds are on the outside of the plate. You can screw the parts together and work away!
The blow plate has the reeds on the inside so you will continuously need to take the blow plate off to make changes, then reassemble the instrument and test again.
The French Tuner™ helps you do that. Use it to play octaves. The Extended French Tuner™ allows you to tune octaves, thirds and fifths. Use it to tune the major chords. It's easiest to focus on the major chords on the lower end of the harmonica and only focus on octaves for the rest of the plate.
This video only covers one technique - adding solder to the tip of a reed. As a rule, you can lower the pitch of a reed by five semitones and you can raise it by two. You can go much further but you will run into problems with response and technique if you do.
Take material off the tip to raise the the pitch of a note. Take material off the base or add material to the tip to lower the pitch.
If lowering more than a semitone, maybe it's best to add weight for most of the drop in pitch? Here I drop the pitch one full tone. In the process, I drop the pitch much further down and then tune it back up.
The gapping paradox is a reed that doesn't respond unless it is very tightly gapped or a reed that locks up unless the gap is opened too much. It's either all or nothing. In both cases, the instrument is no fun to play no matter how you set the gaps. The Gapping Paradox is also the expectation that the only setup a harmonica needs is gapping.
Sometimes gapping doesn't work.
Gapping is adjusting the height of the tip of the reed at rest.
The height from the reed plate determines how much breath it will take to get the reed to play.
Best practice is to adjust the gaps so that the reeds all respond to the same breath. If the instrument offers you enough range, you can fine-tune the reeds to best suit your breath force habits too. Some players prefer harps to respond best to hard breath and some prefer harps that play with less air.
There is an expectation among harmonica players that the only setup skill you need to learn is to gap a harp "to your preference".
We all know this is false. There are times when you can't get the reeds to respond unless the gaps are way too tight - so tight they are not playable. And if you open up the gap even a little bit, the note becomes sluggish or plays with too little power and bad tone.
Likewise, we see reeds that lock up unless the gaps are opened up far too wide which makes both the blow and draw notes too airy and very weak.
This is the gapping paradox: It's either all or nothing.
When faced with this paradox, most harmonica players come to one of two conclusions:
1 - "It's my fault, I'm terrible at gapping. There is some secret extra skill to gapping that I just can't tap into."
2 - "This harmonica is a dud. There is nothing anyone can do about it."
Usually, both conclusions are false.
When you run into the Gapping Paradox, understand that to fix the problem you need to go beyond gapping.
It's the harp's fault. It is a victim of mass-production syndrome. It's not possible for a factory to churn out perfectly-adjusted defect-free instruments unless hours of work are spent on each one. But it doesn't mean the harp is a dud, either.
In most cases, the defect(s) can be corrected in a matter of minutes.
Foundational problems include warped or bowed reed plates and combs. Another foundational problem is a reed that's off-center at the base.
Bowed reed plates are particularly sneaky! In addition to making the harp leaky, you can be fooled by gaps that seem to change all by themselves.
You can adjust the gaps to your liking with the covers off only to find that the harp is completely reconfigured every time you put on the covers. This is because the covers are changing the shape of the slots as the screws are tightened. You are putting tension on the bow.
A bowed reed plate can also make you think there is a problem with the reeds' shape. (See below.) But the problem is that the slot is not a straight reference (it's bowed!) Always address foundational problems before you consider reed work or you will be working against yourself.
Gaskets can help relieve air leaks but they don't make the slots straight. The best solution is to straighten all components.
With a little practice, you can correct the flatness of most combs and both reed plates in a matter of minutes. I offer tools to help with this which allow you to see the curvature and fix it.
Off-center reeds can be aligned at the base. See here.
Reed shape problems are another common cause of the Gapping Paradox.
Gapping focuses on the very tip of the reed. "The gap" is the height of the tip of the reed by definition. Think of reed work as gapping the whole length of the reed. We are adjusting the height of every part of the reed from base to tip.
For example, if the middle of the reed enters the slot before the rest of the reed, there is no amount of gapping that can make that reed perform well. This reed will always disappoint you until you fix its shape.
You can find more details about reed work in the second half of The Grip video and on my USB videos
Again, with a little practice you will be able to fix obvious problems with reed shape in a matter or minutes. This will turn that dud harmonica into a fully-functional part of your collection.
You can do it! A little bit of knowledge and an afternoon of practice can make all your harps play better, save you money (don't throw away a dud) and give you more confidence.
It's made of sturdy carbon steel that is very thin and very springy. The big change is the blow reed support tail. I recommend filing side-to-side rather than front-to-back. I am finding this is the very best way to tune a blow reed on the comb without altering its shape.
Everything affects tuning (even tuning!) so it needs to be the final job. Tuning cannot undo previous work because that would create an endless loop. So if tuning technique messes up the reed shape, we're going backwards.
What about a rotary tool?
There are many ways to feed a cat so everyone can have their own realities when it comes to getting these tasks done but I have found using a good file is the most consistent and least invasive way to tackle tuning.
Nine times out of ten, if you put a good quality file in someone's hand and offer them rudimentary advice on how to use it and avoid causing damage, they find success.
Side-to-side tuning is nuts!!! Do I need a "sharp" edge on the tip of the reed?
There is no evidence that a 90 degree angle is necessary for the tip of the reed to be efficient. In fact, a chamfer will reduce drag. The short segment of the tip of the reed is rather insignificant, though. So if you prefer to avoid the brightness that comes from aggressive chamfering, don't worry about that wee little bit - you won't be able to tell the difference. Just don't shorten the reed!
"Should I direct material removal towards the midline and away from the edge of the reed?"
Removing material from the midline of the reed is probably suboptimal. A sleek reed tip will conserve more energy than a convex soup spoon shape. We don't want to move air, we want to move reed (through air.)