Pterocarpus Erinaceus

Pterocarpus erinaceus: wood used to make musical instruments in West and Central Africa. Used for, among other things, djembe and mbira. The native Shona word for this tree is mukambira.




I had noticed that the wood on many mbiras I saw was similar to many of the djembes I have seen- but did not resemble any hardwoods I am acquainted with. Turns out most are made from this tree.

It also turns out P. Erinaceus is part of the legume family, as are the rosewoods that are so desirable to luthiery as tonewoods. Also in the legume family are acacias (incl. Koa), locusts, bubinga, wenge, and purpleheart, among others.

Kid Kalimba Month!!!

SPECIAL HOLIDAY NEWS!

Blinknow.org and Holiday donations &
Kid Kalimba celebration

A friend posted this video online, which I found incredibly inspiring. Maggie Doyne did something I think we all at some point wish we could do: give our lives over to the betterment of others. But I found her amazing story so refreshing and inspiring:

Maggie Doyne — Why the human family can do better from The Do Lectures on Vimeo.

So I decided to DONATE 10% OF ALL SALES TO BLINKNOW.ORG through January 2014.

At first, I thought, I should move the family somewhere we can devote our lives to helping others. Sure it would be a major disruptive change, but it is the right thing to do.

But then I realized, despite the best intentions, we are not all meant to do service work. I could give you a dozen reasons why that would be a horrible idea, for me personally as well as my family. Is this a copout? Not really. I intend to volunteer (and encourage my kids to) on occasion for any projects that I can find throughout my life, but that is not the main fulfillment of my abilities and passions as a person.

I also realized, that in my own way, I CAN help people directly- by donating money I make doing what I love, and doing what I am good at, I can devote my life's work- making musical instruments- (at least in part) towards helping people.

So to celebrate, this is KID KALIMBA MONTH!

These instruments are made for kids, make great gifts for the holidays, are crafted from local sustainable materials, and part of the proceeds go towards helping children!!
Buy One Now

Buy as many as you can for the kids you know, and tell your friends about them as well!

Happy Holidays,
Josh

Jarana Veracruzana repair

This instrument is interesting in many ways. It is made of a nice smelling pine-like wood most likely endemic to the region:

The entire back, sides, neck and pegbox are carved from a single solid piece. The only glued on parts are the soundboard and fingerboard!

In this shot you can sort of make out how the sides were carved out before the soundboard was added:

And here you can see the back, neck all as one piece. It may look like a glued joint, but it is one continuous piece for the entire thing!

The other interesting thing to note, is that although the strings are separated at the nut into 5 distinct courses, for fretting chords, at the bridge all 10 strings are equally spaced:

I think the intention of this design is to have an even sound strumming across all 10 strings. There would be little melody playing done on an instrument like this.

In jarocho son music, the rhythmic strumming is very important. This type of instrument provides rhythmic strumming, and chords, while other instruments and singing would provide the voice.

I love seeing how instruments are built suited to a particular style of music.

Drumroll please.... here (hear) is the sound of the Esraj with mylar head! Kishan Patel does an amazing job in this performance:

Esraj final

One portion of the rim epoxy came loose after gluing; the job was salvaged by heating and molding the shape of the mylar over the rim, and gluing it completely around the edge with a 3M adhesive, Super 77. The stuff was very gooey and gross to work with, but did the trick- strong tack and fast, durable bond.

Here we are tuning and setting the bridge position:

And it was just in time! Here is a photo from a few days later, in concert with Arijit Mahalanabis, Samir Chatterjee, in the very able hands of Kishan Patel

Esraj head gluing

Here she is stretched on a frame:

and now with epoxy and clamps and weights (I eat heavy peanuts):

Fiberskyn esraj head replacement

I do work on North Indian instruments quite often; sitar, sarod, tabla, etc. People have asked about replacing the traditional sheep or goat skin with a synthetic material, and now I have the opportunity to test it out.

This esraj had a large chip missing from the bottom rim of the bowl. I removed it, squared the edges, and prepared a piece of cedrela oderata which is an excellent match visually and for strength/weight ratio to patch it.

I shaped the new piece to match the rim, and scraped the excess sheep hide and glue from the gluing area of the rim. The patch ties in to a vertical support beam- one that is VERY sturdy- which will carry the string tension through to the neck. I am very confident this repair will hold, even with the very many strings putting tension on the assembly.

The next step is to test adhesives on the Fiberskyn head. Remo makes this excellent synthetic imitation skin. I chose the ambassador weight which is 10 mil thick. This matched a few samples I measured of the sheepskin from the instrument.

The material is mylar, and I opted to test three adhesives: cyanoacrylate (super glue), E 6000 (an industrial adhesive for exterior gluing on cars- recommended by 'the glue guy' at the hardware store) and long-cure epoxy.

I made a scrap assembly resembling the bowl. First I only glue the pieces to the top side of the rim (not wrapping around the edge for extra strength).

I applied some finger pressure, and both the epoxy and super glue broke wood away before giving up the bond. The E6000 bond broke quite easily; I would say I was only applying ca. 20 pound of finger pressue.

Next, I reglued the samples OVER the edge, to add strength. This mimcs the traditional attachment, and will really test the adhesives. Here is the result:

As you can see, I was able to clamp the mylar clear to the bottom of the channel; I would estimate forces in excess of 250 pounds and both the superglue and epoxy held fast. The mylar stretched to accomodate the pressure, and the glue bond held.

However, the E6000 let go after only a few turns of the clamp. Clearly, E6000 adhesive is not formulated to bond mylar.

I will feel very confident using superglue or epoxy. The epoxy was easier to bond the top of the rim with, so I will probably use it for that purpose. The superglue was much easier to use pulling the extra over the edge: the result also looked cleaner, and since that is the most visible part of the repair, I will probably use superglue for that.

Chromatic kalimba: possible tuning layouts

A customer recently asked me about potential note layouts on chromatic kalimbas.

I have crafted instruments with chromatic notes immediately adjacent, in linear ascending fashion, as well as Hugh Tracey style, where the chromatic notes are on the back surface of the instrument. I have also found a nice way to combine approaches, and essentially take the Hugh Tracey diatonic layout, and add chromatic notes adjacent to each pitch. This gives more pitch separation than the linear layout, but less than the Hugh Tracey arrangement.

I am not a physicist, so I have to go on observation of the work I have done.

I have found instruments with chromatic notes closer to each other to have more pitch separation. C and C# have very few overtones in common, so notes struck tend not to excite their neighbor notes by harmonic resonance. If there is a loss in sustain (from the fact that the note is not supported by sympathetic resonance of nearby notes) it is so minimal as to be not noticeable. And, a well-constructed kalimba could be built using dense woods to enhance sustain and clarity.

Hugh Tracey-style puts triad notes (chords) next to each other, giving a harmonic resonance- a very rich sound where the notes tend to blend into a wash of whatever the scale its tuned to. The harmonic similarity is only skin-deep though; if the instrument is tuned to equal temperament, even the I to V relationships are very slightly out of tune, and have little overtones in common. There will still be more overtones of a similar, if not exactly equal, resonant frequency.

Therefore, my idea is that if you want more of a modal, harmonically rich sound (sounds great, but only in the given mode or key) then go Hugh Tracey style and separate the notes as much as possible by grouping into triads. If you are musically more adventurous (most people using chromatics are!) then use whichever key arrangement gives you better access to the notes- the pitch separation will be there and I don't hear a major loss of resonance or damping by neighbor keys,

It is interesting to note that Zimbabwean mbiras are tuned with ascending scale tones immediately adjacent. The right hand notes are half and whole steps apart. There does not seem to be a problem in terms of richness of sound and resonance there!