Success is sweet.  (updated thrice: my Jammer is now colored)

Two Axis-49s tranformed into a jammer

It''s been a looooonng road to trudge, but finally, at last, I have assembled a full-fledged jammer, the musical instrument of my dreams, and the closest approximation of the fabled Thummer that we are ever likely to see.

Jammer #3

2 axis keyboards in folded-scale mode, one for each hand, 98 keys under each hand.

A black Korg nanoPad: my pitch bend and special controls / triggers

A white Korg nanoKey: this is my foot-pedal to-be.

Unseen: A modest little program running on a netbook whcih glues it all together.

Now the real work begins: managing expectations and learning to play the thing.

First. a separate keyboard for each hand

Rationale: key-to-note assignment can be made symmetrical, so one can transfer skills between hands, halving the number of fingerings to learn. Further:

• Each keyboard assignable to a unique instrument
• Each keyboard assignable to overlap the other to a variable degree, making "special" effects like contrapuntal motion simpler, even trivial
• One's hands won't run into each other
• Two keyboards make a smaller package than a single, long one
• They can be put on a table, on a stand in front of the player, on the chest, or held like a guitar
• Far more ergonomic, as they can be angled and positioned to suit
• Ends the tyranny of the right-handed keyboard on the left-handed

Second, an ergonomic key-to-note layout 

A consistent layout (isomorphic) layout is essential. This reduces the number of key combinations to learn.

Third, an efficient key shape

Fifth, compact keyboard dimensions

Wicki layout: minimum of 5 rows high 2 1/2 octaves, up to 8 rows (4 octaves)

    Width: Absolute minimum: 6 keys, better: 7- 10 best: 12-14

Axis layout: minimum of 6 rows high: 2 1/2 octaves, up to 8 rows (4 octaves)

    Width:  Absolute minimum: 7 keys,  best: 14

With my 4-row jammers I find 4 rows; 2 octaves is cramped, and sometimes must use the left hand.

I'm aiming for a unit that I can just pick up and start playing in the same key as my buddies, wider (~10 keys) is better for this, as you can guess the key, then adjust the hand position to the right key in seconds.

The net dimensions turn out well: each keypad is under 20 cm by 20 cm (10 inches square), making for a compact, portable keyboard.

Sixth, ergonomic foot pedals

Two pedals - normally for sustain, one for each keyboard

They should have a Velcro bad so they can be joined together, or separated, one for each foot.

Note that they don't have to be plugged into the keyboard, instead they should be plugged into the computer. 

Seventh, ergonomic special controls

What twit placed the pitch and special effects mod wheels way, way off to the left side? Clearly it was the keyboard engineer, and the dolt thought purely of his own convenience, not the musicians'.

Special effect controls should be put on the bottom to be reached quickly, using a joystick (2 dimensions of control at a finger's touch) instead of huge, clumsy wheels. I suggest either keyboard-mounted like on the Thummer as the ThumStik (patented BTW!), or as I suggest, mounted on the hand and attached to the thumb-tip

Ditto for the special controls like octave-shifting and key-modulation: put them near the fingers or thumb!

The "ideal" Jammer

So, how do we achieve this lofty "ideal"? Forthcoming ... 

Notes:

Future wish list

1. Jim Plamondon, of Thummer fame, did a extensive analysis on the optimum shape and patented his deductions: it turns out that if one leaves a gap between keys and makes them oval in shape, one can get a considerable reduction in spacing, to 15mm or less, permitting nearly twice the number of keys to be easily (and quickly reached). This would be the "sports car model" for keeners. Refinements like this can wait.

3. More features
Acceleration - on a piano the hammer-head's shaft bends, adding an quirky acceleration factor (it changes the string bounce) that allows the percussion and timbre of the notes to change. Try using the finger tip vs the flat of the finger (gives different acceleration profiles) on a piano key - you should be able to hear what I mean.
Aftertouch  - This gets mixed reviews; many new keyboards have dropped this feature. 

Hi loyal readers. You sure are a varied lot.  See: my site monitor  .

While work goes forth on the Generalized Keyboard conversion kit, I'm refining the design of the jammer.
I had to take it apart to analyse the keys and to show to plastic makers. Now I'm improving it as I put it back together.

The main change is invisible: I've tuning the keys to the same, much lighter weight, so that I have more hope of learning to play it well. when first constructed I was happy to have a working instrument with all keys that worked and had pianoforte. Now, as I learn the details of construction and the mechanics of playing, I'm getting more fussy. When I measured the pressures required, I found they were way out of spec. The good part is that, now that I've found this out, others are saved the work.

But enough of technicalities. On to the important things: gadgetry.
Can you guess what I'm going to do with these items?

WhatIsIt

Ken.

Update: Here's what it looks like after the 1st assembly, but before refinement and styling.

JamStik 1st assemly

What if there was a musical instrument that was easier to learn, faster to play and best of all, provided a special insight into how music comes into being?

Herein I present the “jammer”, an innovative musical keyboard design, and why it’s so cool.

The 12 notes of the scale

First, let’s design a music keyboard from scratch, as if you’d never seen one before.
There are 12 notes in an octave,
     spaced apart by a semitone. 
     Two semitones steps make a wholetone.

Step 1: Lay out the keys in one row all equally spaced by semi-tones, like this, and you have the layout of a harp's strings.

Twelve notes on two rows

But unlike in a harp, we don't have to be linear, and we don't have to base our design on a early harp-like instrument that only had the C-major scale's notes.
Next: It makes sense to stagger notes so they alternate: 

And slam them closer together:

Notes of the major scale

So far so simple. If you play all in sequence all 12 notes you get a chromatic scale, presumably so named because it has every color of note on the scale. Most musical scales are whole tone based, with the type defined, largely, by the notes they skip, and when they sneak in a semitone jump. With this layout, a major scale goes as shown right:

If you add a third row on top, then you can play any scale, in any key using the same pattern.

Playing major scale on jammer

You have much less to learn – 1/12th (!) as many patterns as on a standard piano keyboard.

This is the Janko pattern and is over a century old.

It's also a trifle bulky, as you can see if you click the above link.

The technical term, used (I suspect) to either scare off non-geeks or to sound intellectual is isomorphism. I prefer the term consistent-interval, or simply consistent. (Personally I bet we'll one day hear the term in a science fiction show: "he's gone isomorphic, Jim")

Compare to learning the piano as show here:

Playing major scales on piano

It was first designed without black notes,
and its totally designed around the C-major scale. 

Other scales are fiendishly hard to play.

It's rumored that the Janko pattern was scuttled, despite being favored by noted pianists, by piano teachers. Bad people!

That’s easier to learn – what about easier to play?

While the Janko pattern is cool, it flopped a century ago, and perhaps not all the blame lies in greedy piano teachers. After all, pianos are hard to lug around, and an reduction from learning 12 (!) fingering patterns to just 1 streamlines only one part of the playing experience. After all, the simple alternative is to just learn one pattern as was often done.

Can we do better? Can we take advantage of the fact that some notes are physically adjacent? Normally on a piano you’d seldom play adjacent (Black and white) notes.

The patterns the thing

Lets look at the important notes in the scale. In all scales there’s a special note, the Root, it’s odd twin the Octave,  shown in green on the right.

They have special partners the 5^th and the 4^th, also know as the dominant and  sub-dominant. 

Practically every musically useful chord pairs a root or the octave with the 4^th or 5^th. With a linear layout, the useful notes are spread out and you have to bop around a lot: great, big hand motions are needed, and the piano keys are big and heavy because the thumb also has to be able to play them.
And ... you can’t wear a piano, or even carry it to your next gig.

Spaced out notes!

If we slide the notes in the second row over a bit, the 4^th and the 5^th can be put right above the root.

Consequences both simple and a bit bizarre:

• On the third row above, the octave naturally appears above the root, between the 4^th and 5^th. All the important notes touch.
• The design is brilliant. My thanks go to the inventor, Brian Hayden.
• We can play the commonest useful pairs of notes with one finger.
• Thus suddenly almost every chord needs one less finger - often two!
  

  Less 'Spacey' notes
• Add a few more rows and the hand movement needed to switch octaves drops from feet to mere inches.
• Instead of moving the hand a lot left and right, just the fingers have to move a bit up and down
  
• Bizarre side effect #1; it gets harder to play wrong notes, as the dissonant pairs have been pushed apart. 
• Bizarre side effect #2; you can play new patterns with your hand turned sideways.
• Since the keys are closer, one can play more exotic and interesting chords with one hand - you can jam!

And there's more:

• The thumb is free to do cool things to the sound, as is shown at thummer.com.
• The human brain is wired to think in this pattern, so players understand it deeply.
  

So there you have it – here’s an instrument that you can play in any key, significantly faster, and as I show in the next segment, also allows you to jam, improvise, arrange, understand and therefore teach music far faster.

So how do you get one? You either join the ThumClub, and lobby for a Thummer(tm) (joining does not seem to get you more than 2 emails a year, for those spam-shy), or build one. I, naturally, recommend both.

Thirds are OK too

* We'll deal with thirds later; they are a fully a topic on their own.

* Also note the this idea is not unique, a guitar's strings mostly go up in fourths (4th, 4th, 4th, 3rd & 4th to be precise), and some guitarists tune all their strings up in perfect fourths, violins strings are always tuned up in perfect 5ths. Finally, European accordions (concertinas) have this precise layout, known formally as Wicki-Hayden.

Downside:

Thus far, I don't know of much in the way of problems with this system, except that its a touch more complex (at first) than the Janko system. Even playing a chromatic scale (ascending semi-tones) is easier than on a piano.

Gavin Healy, one of the world's first jammer players, wrote:

"What I found amazing is that the Thummer taught me patterns of intervals like this one: whole-tone, whole-tone, semi-tone; whole-tone, whole-tone, whole-tone, semi-tone – which defines the major scale. This to me was like a revelation; I could simply remember this pattern and automatically transfer it to my instrument of choice. I felt like this was a hidden secret of music theory. Instead of learning all these different fingerings for scales, chords, progressions etc on the piano or whatever instrument when I was a kid, I could have been taught the geometry of music which actually makes more sense." 

Just fold it over

How to make a “ZipEx” style jammer*

Riddle: How do you make a 4-row hexagonal-key instrument from a 2-row piano-key one? 
Answer: you fold it over and replace the keys!

Background:

Update: I've since made a second generation version, the ZipEx Mark II, the basics are still the same. This rebuild-from-the-PC-board-up way was much harder but resulted in a smaller, wearable version. The Mark II is heavier, but much easier to build. Ken.

A typical electronic keyboard has 2 parts, one is the music control thingy, I’ll call it the controller, and the second the key holder assembly itself.

I have examined just 2 keyboards, A Yamaha DjX, and a Technics P50, but I suspect most are pretty similar.

The key board electronics is on two loooong printed

DjX keyboard PC boards extracted

circuit boards (PCB) clamped into the key assembly. The two boards are connected to each other by a single 6-inch, 12-lead wire, and one of the boards in turn connected by a 10 inch or so, 6-lead connector to the controller.

Each long PCB has clamped onto it a bunch of rubber buttons which make a little dome about 2-3 mm over the PCB. These buttons are depressed when the plastic keys of the keyboard assembly are depressed (I'm not sure what makes them happy).

The underside of the little dome buttons, the part clamped to the PCB, has a little bit of conductive black graphite paint on it, and when it hits the PCB, it closes a circuit, and the circuit generates a signal that the controller interprets.

DjX Keyboard PC board

On the Technics keyboard, each key has two buttons it depresses, presumably at slightly different times to denote a key's velocity.  The Yamaha has a double contact set within each button and the contacts are of slightly different length, thus also hinting at the key's velocity. The important thing here is that you don't need to know further detail on how it works, or electronics.

In my design, I used just the pc boards and the rubber buttons, and rebuilt the key holder assembly.

List of materials

• A keyboard to cannibalize - I used a second-hand Yamaha DjX,  $60
  
• Clear plastic about 3 mm thick for the base – I used a piece from a vinyl window. One should be able to get this from a glass window shop.
• 70 plastic or metal posts – allow extra 10 for wastage - a set of 19 mm nylon spacers for PCB boards worked well here. 
• Material to make 70 plastic or wooden keys. I used Douglas fir for Practice, and settled on Maple rather than Oak
• 35 springs – I cut them in half, as they were expensive, @ 80 cents each. Drop a comment if you need a supplier.  
• 70 key caps.  – made from thick plastic sheets – I have some extras I can send to you. 
• The keys caps were attached to the key-tops with double–sided tape.
• Lots of bolts to attach the posts to the base and to cap the posts
• A tap to thread the posts so the bolts could screw onto them.

Tools

• Drill press with depth control
• 

  ZipEx Half Built
  Drill bits in 1/64" gradations
• Sander is handy
• A protractor, ruler and a compass.
• Several colors of fine-tipped Felt pens to mark up the plastic
• Table Saw to make the keys
  

Software

• Needed is some way to remap the keys to different notes. I used MAX/MAP, an expensive program @ $500 (I have other uses in mind for it, so felt it's price justified). One might be able to use Java, or in a pinch, I can compile my Max version and send you a runtime.  

Layout – the pattern is drawn on the [plastic with fine-tipped felt marker pens.
The spacing between key is determined by the average inter-key spacing of the switches on the PCB, and simple geometry.

The key spacing on the PCB is slightly irregular, due to the irregular placement of black keys. This made things a bit complicated, as the buttons didn't line up with the jammer keys.

ZipEx key

.

There are two ways discovered thus far to mount the circular or hexagonal keys for the jammer:

• mount them on posts - this is fairly fiddly, as 60 sets of holes have to be drilled, and each set is of 8 or so individual holes in addition to making the keys themselves. There were also problems removing friction.
  
• Mount them on little arms - I have not tried this way, but will use this for my mark II version. 
  

Update: Johannes Drinda asked how I made the keys.

====================================

ZipEx Finished

Here's the end product. In addition, the pitch-bend wheel was mounted in the corner and a brass rod attached. 

The black keys at the sides (one PCB was 6 notes longer than the other, so there was overhang) are octave-shifting function keys, used to make it pretend to have more rows and keys. In effect I have a 96-key keyboard that pretends, when needed, to be two keyboards, one for each hand. The blue-black keys in the center divide the two sides of the instrument, and are dynamically assigned to whichever hand is playing near them.

With the special function keys, it's surprisingly easy to play in pretty much any key.

The case was easily made out of brass angle-iron and the leather strap bought at a guitar shop.