Andrew's blog

Essential Tool Kit

My tools are expensive!! I put a lot of work into each piece. They are the exact same tools I use on my workbench when I customise harmonicas. I know they work well and will last a long time.

I've added a minimalist kit to my tools so that you can make your own choice about what you need and save some money.

The Essential kit is my Basic Kit with fewer add-ons and it doesn't include the Grobet file.

Tuning is an important aspect of harmonica maintenance but it may be less important to some players. For those folks, I offer a method that uses easily obtainable 120-grit sandpaper to make tuning adjustments using my reed support tool.

As with my other kits, email support is provided with the purchase of these tools. Within the first 90 days of purchase, I will answer any question about using the tools, just email me your questions.

See the Essential Kit page.





LIVE sessions January 2024

I will be holding some online live sessions in January.

Please see the links for date and time as well as to register.

Placed are limited so please register to save your spot!

1- Basic assessment of an out-of-the-box harmonica. How to see the defects objectively. How to prioritize your work to correct these defects and be able to get the most improvement in the least amount of time.
Session #1
January 13th at 11:00 EST, 08:00 PST, 16:00 GMT

2- Maximise power. Get the most decibels out of the flow of air from your breath. Demonstrate the important foundational work of the instrument, enhancements and reed work.
Session #2
January 13th at 12:00 EST, 09:00 PST, 17:00 GMT

3- Tone. Your instrument shapes the sounds you create. Here's what you can control to get the tone you want.
Session #3
January 14th at 11:00 EST, 08:00 PST, 16:00 GMT

4- Control. Regular notes, bent notes and overbends. We will go through the details of making reeds play stable, musical, responsive and easily initiated overbends.
Session #4
January 14th at 12:00 EST, 09:00 PST, 17:00 GMT

I look forward to seeing you in a session!

Weird Science

If reed work seems like an occult art or weird science, or if embossing feels like a dangerous idea, maybe you aren't looking at things the right way. Maybe you don't understand what you are seeing or what you should be seeing?

Here's a hint. Tilt your phone.

If you aren't reading this on a phone, print it out!

See also this post from a few years ago around the same subject. It has a video!

From an email: Common question about temperament

"I play ... blues, simple jazz, little country. I play single tone, multitone, chords, arpeggios (triades, 6th; 7th), different modes (or positions). Tongue blocks, splits,
What kind of tuning is optimal for my style of playing?"

"Hi ---,

Since you play single, multiple, chords and arpeggios but you also play in different positions, the answer is not straightforward. But the problem may not be too big, either...

If you have played both stock Golden Melodies and Stock Marine Band or Special 20s, you have experienced both temperaments. And if you don't have a strong preference at this point, then either temperament should work for you - the question is which do you prefer? How important is it to you? Is this really a big problem?

If we focus on the reeds that are tuned as major thirds, that's the most noticeable difference. So holes 2, 5, 8 blow and 3, 7 draw are tuned about 12 cents flat on Marine Band type harmonicas. When playing in positions/modes/scales where those holes are the tonic or the fifth, I feel like that's where it's the most noticeable. The single note is flat and if that's your tonic, the whole scale may seem unstable. Or for example, the major scale in third position - the second and the sixth note on the bottom octave feel a little off. They would feel better in equal temperament.

But if you tune those notes to be equal, the major triads and even the splits can offer less power, less harmonics. One of the features of a custom harmonica is the precise tuning which provides powerful harmonics if you tune for harmony. The sound from the major triads in harmony can fill the room (as Joe Filisko says, little instrument, big sound!)

I am sorry but you can't have both! Not on the same instrument at the same time, anyway. So the choice is a matter for you to decide. But I hope I have given you the information to make that decision. Please let me know if you need me to elaborate further.


Off-menu items

I offer two harmonicas that are not listed on my Custom Harmonica page. They are variations of my custom harmonicas.

CAD$55 less than my Full Custom
Order a Basic Custom

Special 20/Rocket CAD$150
Marine Band Deluxe CAD$175
Order a Reconstructed N.R.W. harmonica

It's a little bit like going to a restaurant and ordering something that's not on the menu.

I try to tailor each instrument to your needs and I keep the Basic custom or NRW options open for specific cases.

I'd rather start the discussion with what a Full Custom can offer and suggest a Basic Custom if the player would not benefit at all from the extra customisation.

I used to feature my Basic Custom harmonicas along with my Full and Overbend custom harmonica as a budget friendly option. It's a great choice for a player who only ever uses second position.

But the truth is, I have found it difficult to start from a Basic custom harmonica and try to meet some extra needs beyond its intended scope.

I usually end up creating a custom harp that's an awful lot like a Full Custom, and that means I have spent the same amount of time and effort customising it as a Full Custom.

I'd love to keep doing things that way, but it's not sustainable.

It's not easy to tell a player who is really set on a Basic custom that I feel they would best be served with a Full Custom because it feels like I'm up-selling.

So my Basic Custom harmonicas are now an off-menu item. They are CAD$55 less than my Full Custom.

The other off-menu item is new: A Reconstructed or NRW harmonica™.

A Reconstructed NRW harmonica™ is not a custom harmonica because it does not feature high-performance reed work.

Whereas a custom harmonica does most of the work for you and is played with little effort, an NRW harmonica™ is played with regular breath force. As such it is the best choice for players who cannot use breath control.

Every player secretly hopes to "win the lottery" and get a "really good one" when they buy a new stock (non-customized) harp from the music store.

A Reconstructed NRW harp™ exceeds that expectation because attention is paid to every detail of its foundation as it is rebuilt. But it does not feature custom reed work (reed shaping). It aims to be powerful, consistent from top to bottom and in perfect tune.

My Reconstructed NRW harmonicas™ are CAD$150 to $175.

See more information about my custom harmonicas here (The Menu)
Order here.

"How do I make my harmonica play like a custom harp?"

"Surely, there's one secret thing you do?"

Well, it's not that simple....

When two Hohner Affiliated Customizers talk shop from Andrew Zajac on Vimeo.

When two Hohner Affiliated Customizers talk shop and all you want to do is play a nice harmonica.

Replacement reeds odyssey

Reeds are metal springs. They are made to convert the kinetic energy from the flow of air into decibels by vibrating though the slot of the reed plate.

Springs can last a long time. So can harmonica reeds. But there is no expectation they will last forever. They go out of tune and they break. A reed can be re-tuned without any loss of power or tonal quality many times before it fails.

With good technique, I feel it's reasonable to expect to have to adjust the tuning of your harmonicas every two months or so and you will have to replace between 1-3 broken reeds per year.

You can change harmonica reeds yourself. You will need tools to remove the bad reed and tools and supplies to attach a new reed. It doesn't matter which method you use to attach the new reed to the plate. Use a rivet, use a screw, buy a welding torch and weld it on. Pick the easiest, most accessible method and get good at it (Use a screw!)

To learn how to replace reeds can take practice. You must not only take off the bad reed and put in a new one, but you must not damage or warp the reed plate while you do it. You must also adjust the shape of the new reed so that it plays well. And once you have done that, you need to adjust the tuning of the reed since it will likely be off. Even the slightest change in a reed's placement on the plate will change the pitch.

You can scavenge reeds from other harmonicas of the same make and model to replace broken reeds. You must use a reed of the exact same size from the same slot of another harmonica. You may use a reed that is 1 to 4 semitones higher and tune it down. A really easy way to tune down a reed is to use BLUTAK:

It's more difficult to use a reed of a lower pitch and tune it up. It can be done. Don't try to raise it more than one semitone. Any more than that and you will not like the tone. And it's too much work to be worth the effort.

Hohner Marine Band type reeds use two different slot configurations. Long Slot are used for keys of C and lower. Short slot is used for keys Dd and higher. This can complicate things since the size of a 6 slot in a D harp is different than the size of the 6 slot of a C harmonica.

Still, you have lots of options. See this chart for Hohner MB, GM, Special 20 and Rocket reeds:
Reed Chart Hohner

You can buy new reeds from the Hohner and Seydel factories. There is no such option for Suzuki nor Lee Oskar.

It's straightforward to buy packages of three reeds from the Seydel website.

It's easy to buy packages of five reeds from Hohner from their USA/Canada shop. Go to

For the rest of the word, you need to use the website. At the time I am writing this, the links to single reeds are broken.

They can be found as you navigate for diatonic harmonica, Marine Band type parts. They offer a product that is quite expensive which includes five pieces of all 20 reeds for a key.

I don't think that's a smart investment. Mostly reeds 4, 5, 7 and maybe 9 blow out the most frequently. You do not need to have five extra reeds for all the other holes.

If you select a key, you will be shown the individual notes and reeds on the bottom of the page. If you click on one of those notes, you should be able to add a pack of five of those individual reeds to the cart. But those links are broken.

I suggest you use the contact page to ask about ordering individual reeds. Specify the key, the hole and whether it's the blow or draw reed you need. If you want to use rivets instead of screws, ask them to supply you with some rivets. They usually can provide them in sticks of 50. They are excellent and you can use them on Seydel harmonicas.

Half-Step bends

The size of the top four chambers are significantly smaller in a Short Slot Dark comb™ than a Long Slot (standard) comb. This helps you match your embouchure to the resonance required to control the first semitone blow bend on the ten hole.

If you are struggling to hit that note cleanly in a higher key diatonic harmonica, don't be hard on yourself. It may not be your technique. It may just be physics.

The smaller overall space of the slot decreases the amount of compressible air in the system.

More importantly, the depth of the slot can affect what frequency is reinforced by the channel. The reed dimensions and weight distribution determines the frequency obtained when air flows through the slot and past the reed. But the slot itself can want to behave like a pan flute and the column of air can compress and expand at it's favourite frequency.

On the top end of the harp, it's difficult to compensate for that using your own embouchure alone.

The back wall of Short Slot combs' holes 7, 8, 9 and 10 are closer to the opening than those of a long slot comb. This changes the frequency that is reinforced to one that does not compete with that first semitone blow bend.

You can't change the laws of physics but you can change the slot sizes so that physics works in your favour!

See more about my Dark Combs™ here: Dark Combs

Altering Standard Richter to Spiral Tuning

Spiral tuning has the notes of the major scale alternating between the blow and draw notes. It provides draw bends and overblows from holes 1 to 10.

It also provides a lot of chords. You can add a major or minor seventh to many of the
chord triads shown here.

You can alter the tuning of a Standard Richter harmonica to Spiral Tuning.

Here is a visual aid to the modification:

Shown above are the offsets in semitones. You only need to lower the pitches. And you only need to modify 12 of the 20 reeds.

You can use solder. You can also use BluTak which is a very effective and stable way to lower the pitch of a reed by several semitones. It's the easiest method, too!

Second Position Spiral is another alternative where the tonic is the 2 draw.

The chords available are as follows:

Here are the modifications. You need to alter an extra reed:


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