Nintendo DS Synth Program: “Korg DS-10 Analog Synth Emulator”

Korg DS-10 Analog Synth Emulator for Nintendo DS

One correction: There are now North American and European releases out with appropriate documentation.

By Inside Synthesis

KORG DS-10 is a music creation program for the Nintendo DS that emulates the Korg MS range of synthesizers. Frequently people refer to the Korg MS-10 but this is a single oscillator monosynth. The DS-10 adds sync which the MS-20 is lacking. It was released on July 24, 2008 in Japan, October 10, 2008 in Europe, and November 4, 2008 in the United States.

A newer, DSi compatible version, entitled KORG DS-10 Plus, was released in Japan on September 17, 2009 and in the United States on February 16, 2010. It doubles the number of synth and drum machines. It also adds some minor new features for the standard DS.


The DS-10 creates sound with two analogue synthesizer emulators, each with two Voltage-Controlled Oscillators (the Korg MS-10 had only one VCO). The VCOs feature a sawtooth, a pulse (with a non-modifiable pulse width), a triangle and a noise waveform. There is also a four-part drum machine that uses the same sound creation techniques as the synthesizers. The sounds made by each of the synthesizer emulators are modified using virtual knobs to change the value of standard synthesizer parameters such as cutoff frequency and waveform shape. Additionally there is a screen where users can patch certain parameters to be modified by an LFO, the envelope generator, or VCO2. Those new to Korg synthesizers may find the original Korg MS-10 Manuals useful in understanding the function of its components.


The user interface is mainly through the DS’s touch screen with the cursors serving as a supplementary method of moving through the various interface screens. The primary method of navigating through interface screens is by switching the interface screen with the processing flow map and selecting which item to modify. Notes can be played using a 2 octave keyboard or through an interface that detects the X and Y position of the stylus on the touch pad simulating a KORG Kaoss Pad. The Kaoss Pad can also be used to modify volume and pan as well as being able to assign the X or Y values to any of the parameters that can be modified elsewhere. Users can record twenty-one sessions with sixteen different step patterns with either live input or through a step sequencer. These patterns can then either be selected live or sequenced with the song mode.


The DS-10 features a chorus, flanger and delay parameter that can be applied to each synth or the drum machine individually or as a whole. In addition, each of the editable drum sounds can have a separate effect added to it in addition to the global effect.


BPM PMAs are simple light (don’t take much resources on your device) apps that you can play anywhere. You can play them on the bus. You can take several instruments with you when you travel, and you can edit the instruments depending on what music you want to play.

We design them to be hacked. You can modify your instruments. There is a community to discuss the instruments, hacking on the non-coder and on the coder levels, and other music subjects.

We build new instruments. Instrument designers whose designs we have noticed have their designs translated into digital form.

We build for tablet/phone and keyboard. These aren’t apps designed for a dedicated machine or physical instrument, and translated into a digital form. They are built digital-native. They are designed to be used best when played on a tablet/phone or desktop with a keyboard. They can be used without a keyboard as well. We sell inexpensive portable keyboards you can plug into your tablet or phone — the same keyboards we use ourselves. They are designed to be used plugged into an amp with a band as well, if clients want to use them that way.

We use our own apps. We develop them as we use them. This means that every once in a while, we update the information, the apps, and the explanations on how you can get the most out of your BPM PMAs. It means we develop them so that we will be satisfied with using them. It means we have in mind how to make them as well as possible, get the most out of them, so that we can use them.

What rights do I have when I edit the code?


The code is proprietary. BPM owns the code. We do not permit people to edit any part of the code and give it away publicly, in any form. We do not permit people to use any part of the code in something they sell. The code is our intellectual property and using it in any of these ways is criminal.

Why? There was a LOT of work behind getting this code and these PMAs here. Thousands of dollars, finding coders and instrument designers, communicating. Hundreds of hours working things out, designing, coding the layout, making the samples, figuring out how it could all work together, building the website. All this time, money and energy used for this project instead of one of the other projects we could have developed. We want to be able to at least recover our investment, and want to make a profit on our investment of risk, time and energy, if it is possible.

Keep in mind that profits from this project will fund more digital instruments and improvements (things BPM PMA clients ask for or say would be nice additions — updates for the app they already own which happen free). Profits fund coders who make these apps, instrument designers who design new instruments, and a bunch of other things anyone who buys one of our PMAs can benefit from.


You can buy a legal copy of the app. We have made it inexpensive to buy. Then you can modify this for your personal use. You can share modifications (not share your version of our product) on the forums, and other people can try them out and discuss them. You can share your samples, ideas and layouts, and benefit from what other people share. This way, you can get an instrument that you like to use, that’s personal, and you can change it as needed.

If you happen to make an instrument using our code, you can show it to us. If we like it, too, we’ll market it and give you some of the profits from the sales.

If you make an instrument that doesn’t use our code, the same deal applies, except we’d expect to give you a bigger share of revenue. Again, show it to us and if we like it, we’ll market it.

If you’re a good coder and you make an improvement to our code, depending on how significant the improvement is, we will consider using your improvement, at which point we’d credit you and give you a proportionate cut of revenue from the app you improved.

About the Base Code (Limitations)

Maybe the most important thing you will have to learn: Code is strict. You cannot have a letter xut of place in code. An extra period can cause the entire app to fail until you correct your error. Don’t complain to other coders about it not working. They know all about it. If code is correct, it will work. If you find your app is broken (because you have errors somewhere), you will often have to go back to square one (the basic app code) if you didn’t save yourself a safe-point that worked. Frequent safe-points are advised.


To hack your app without understanding of code, you can edit the config file. We’ll look at the things you can do at this level first.

Example of a working button in the config file (you can refer to this as you read):


workingbuttonThis button is played by KeyQ, and it’s name (which is not displayed on the screen, by the way) is KeyQ. It’s color is #6A287E. On the screen, it shows the label “Q” above it. When you hold this button, it will play again and again, and will play overtop of its previous play if you click it twice quickly. The sound the button plays is located in the “sounds” folder, and is called “drum-bass001” and it is an mp3 file.

LIMITATIONS of the code:



Every button needs its own name (whether it is to be controlled by a key on your keyboard or not). You can name it anything you want, but it must have a name, and the name cannot be the same as any other name. If you name it with a keyname, that key will control the button. If you name it with anything that is not a keyname, no key will control the button.

The code allows you to assign a sound/button to the keys of your keyboard, but not every key on your keyboard.

Here are the keys you can assign:


Here are the names of the keys which you can assign:


(Note: there are names here that don’t work when assigned to keys, usually because when you use a browser to play the app, the browser assigns functions to some keys. Stick to the keys outlined in red above and you should be fine.)


You can assign colors to your buttons (including RGBA).


You can have your buttons display a word if you want (leave blank between two single quotation marks if you don’t want a word). Note that the word will stretch the key size out, which might make formatting your buttons difficult.

Playmode (button functionality)

You can make the buttons do different things: play just once, play over and over again. Cut off when they are clicked a second time. Play over the last sound when they are clicked again.

The language used for this is:

  • ‘play-over’ does not restart on touch. sounds overlap
  • ‘hold-to-play’ plays infinetly only while holding. stops on release.
  • ‘hold-to-play-over’ plays infinetly only while holding. fades out for overlap


You must assign a sound to a button, and that sound must be in the place you tell the config file to find it. If it isn’t there, the app will not work. You must enter the file location in the correct way, so it’s best to start by putting your new sound file in the same place as the file your app already can find, then changing the name in the config, then testing it, then deleting the old file (you don’t have to delete any files, though, you can leave as many as you want in the folder unused).



File Naming Conventions for Samples

The convention is soundtype-001-addendum.

For example:


Most important note: each sound gets its own number, even if its a version of another sound.

This makes it easy to:

  1. Find skindrum sounds
  2. Not confuse sounds because each one has its own number, regardless of the addendum
  3. Add supplementary notes about the sound without disorganizing the filing system


Sometimes though, you can’t stay in sequence with your names. For example, you already have 28 skindrum sounds, and now you want to make a short version of one of them. Best method:


Here, X stands for “child sound.” Using X will keep these files after your parent sound, because X follows other letters and file displays are usually arranged alphabetically.

Example of what it looks like in a folder (in this case, digeridoo and drum sounds). Notice “drum1.” Wouldn’t it be nice if that file had kept with convention?

BPM sample file namig system


Your Purchase Will Fund More Instruments

Your purchase of a BPM PMA will fund instrument designers, instrument builders, as well as BPM itself.

We will be responding to the ideas people propose for instruments and we’ll be making upgrades to already-made instruments according to what people are asking for.

We also have a number of instruments lined up that are awaiting development.

Add yourself to our mailing list to get updates when we come out with new instruments. >Click here<

Dictionary of Musical Terms

These are the musical terms used on this website. You will probably notice that most musical language dates back as long as the Western culture — to the Greek and Latin speaking people of the northern Mediterranean — often repurposed or modified in Europe’s Medieval period, when Latin — the language of the Church and of learning — . 

Equal temperament a system of tuning in which every pair of adjacent pitches is separated by the same interval: The pitches of an equal temperament can be produced by repeating a generating interval.

Just Intonation any musical tuning in which the frequencies of notes are related by ratios of small whole numbers: The two notes in any just interval are members of the same harmonic series. Just Intonation, also called ‘pure temperament,’ can be contrasted with ‘equal temperament.’

Octave a series of eight notes occupying the interval between (and including) two notes, one having twice or half the frequency of vibration of the other [< Latin octava dies eighth day < Middle English octaveii]

Temperament a system of tuning which slightly compromises the pure intervals (adjusting the pitch) of just intonation in order to meet other requirements of the system: Most instruments in modern Western music are tuned in the equal temperament system. [< Latin particular mixture]


Educators, click here …

We are open to coming to agreements on bulk purchases for educational purposes. If you would like to discuss a bulk purchase for educational purposes, email us at __________ and begin your email subject line with “EDUCATOR RATE INQUIRY:”.


Written by instrument designer Nick Collier of Nick’s World of Synths. Nick is a British instrument designer who has created a ton of instruments — besides the Harmonicon on which the Harmoni is based — you’ve never even heard of before. Make sure to stop by his site (click here) and check them all out. 


The Harmoni is a digital version of a real homemade synthesizer. The reason for the strange keyboard is that it is tuned in “just intonation.”

Here are a few notes to help you navigate the keyboard:

  • Octaves are stacked vertically
  • White is the root note
  • Yellow is the 5th
  • Purple is the 4th
  • Red and blue are more major
  • Orange and green are more minor

Follow the colors without mixing major and minor and it should sound pretty harmonious.



Just intonation is the system of tuning that western music used to be based on, so it sounds quite familiar and is easy for someone brought up on modern tuning to relate to. It has also been used my most other musical traditions throughout history and is probably the most instinctive way of tuning an instrument as the intervals can be tuned by ear very easily. Modern equal temperament is not very instinctive, ask a piano tuner how long it takes to learn how to tune all the intervals, it is done by listening to the speed of the beats of the out of tune intervals.

Firstly, we need understand musical intervals as the relative frequency of one note to another. We can use two numbers to represent the frequency ratio of two notes — for example the ratio of an octave is 1:2, which means that the higher note is twice the frequency of the lower note e.g. A-440Hz : A-880Hz, or the fifth 2:3, the higher note does three vibrations for every two of the lower note e.g A-440Hz : E-660Hz.

When using ratios we are just concerning ourselves with relative pitch. We could choose any two numbers to make our interval, but our ears prefer ones based on smaller number ratios. Here is the major scale as ratios.

Do 1:1, Re 8:9, Me 4:5, Fa 3:4, So 2:3, La 3:5, Te 8:15, Do 1:2

do re me pitches

Modern equal temperament does not use these perfect ratios. It has re-tuned them, but re-tuned them by small amounts so they are still recognizable as representing the same intervals.

We can take our major scale and fill in the whole tone gaps to make a 12 semitone scale (picture these two tables as one long row).

1:1 15:16 8:9 5:6 4:5 4:3 √2
Root m2nd M2nd m3rd M3rd 4th Tritone
2:3 5:8 3:5 5:9 8:15 1:2
5th m6th M6th m7th M7th Octave

Seen in this way as simple whole number ratios our familiar intervals seem to have a kind of geometric perfection. The only problem with this system is that the notes are not equally spaced.

Some of the semitones are bigger than others. This means that on an instrument tuned in this way a piece of music will sound different if it is transposed to a different key. In modern tuning, equal temperament has re-tuned these intervals so they are equally spaced, and you can play in any key and the music will have the same essential character. The process of equal temperament in Western music happened around the time that keyboard instruments were being invented.


Compared with equal temperament, the harmonies of just intonation sound purer, brighter and more defined. Equal temperament sounds fuzzy and more uniform. The intervals that have suffered most by equal temperament, namely minor 3rd, major 3rd, minor 6th, major 6th are what the emotional language of Western music is based upon.

Instruments tuned to just intonation I find far more emotional to play. I remember the first time I experimented with just intonation, it was an old electric organ that I re-tuned, I found the sound so captivating and beautiful, I suddenly found I could play away for hours improvising and really enjoying playing music, whereas before I would find it bland and uninspiring. My point is that just intonation could be seen by some as being a nerdy distraction from music making and obscure pointless subject, but to me it is key to my enjoyment of playing a musical instrument and I want other people to experience its beauty.


Just intonation is an open system with no limit on the number of notes that can be added to a scale. While the traditional western 12-semitone scale is just one variation, I have chosen to use it as an example because it is easy for most people to relate to. The system I used on the Harmoni is an extension of this 12-semitone system.

(table of scale but it is the same as above)

You may be wondering why the particular intervals in the above scale were chosen: Is there any kind of formula for making a scale, or is it just a case of adding more and more intervals and stopping before they start become too obscure?

I think the truth is a bit of both.

We know that intervals based on small numbers are good, so this accounts for 2:3 3:4 4:5 5:6 3:5 there are no simpler intervals than these that can be fitted within our octave. But simplicity is not just about how small the numbers are, it is also about prime numbers. If you look at all the numbers in the scale you will notice that they can all be divided by two, three or five. The scale has a prime number limit of five, and this explains why the next smallest interval is 5:8 and not the smaller 4:7 or 5:7.

Setting a prime number limit of five keeps the sound familiar to Western ears. If we use seven as our limit then we get some more exotic sounding intervals. The intervals based on seven always remind me of traditional West African music.

The last four — 8:9, 5:9, 8:15, 15:16 — are all created by moving a fifth away from the other small number intervals, and they also fit nicely into the spaces at either end of the scale.

The √2 is not a just interval, I use it because it is the halfway point between the root and the octave, it is useful because it is a point of symmetry between the bottom and the top halves of the scale. The top and bottom halves are a mirror image of each other, except for 8:9 and 5:9.


(Note: The colors of the instrument have been changed around since writing this explanation. Sorry for the confusion, but it shouldn’t make much difference in understanding this explanation.)

My system is just an extended version of the 12-semitone scale, apart from two notes using ratios of seven, I have stuck to a prime number limit of five. The reason for using more than 12 notes is to allow for more freedom of movement.

temp image of harmonicon


I made my scale by starting with just three fundamental intervals. If we decide to use a five-limit scale, then the only prime numbers we have to base all our notes on are two, three and five.

two, three and five intervals

The three fundamental intervals are made by using combinations of the prime numbers 2:3, 2:5, and 3:5.

temp image

To keep them all within the same octave 2:5 becomes 4:5. So we have 2:3 (fifth) 4:5 (major 3rd), and 3:5 (major 6th).

inverted intervals

temp image 2

These intervals are inverted to make three new ones 3:4 (fourth) 5:8 (minor 6th) 5:6 (minor 3rd).

Another six intervals

temp image 3

Another six are made intervals by adding neighboring intervals. If we try making new intervals by adding other ones together then we just get ones we already have. So only six new ones can be made this way.

six new intervals

temp image 4

Six new intervals are made by adding each interval to itself. These new intervals appear in the web-pattern diagram to be only connected to one other note, but the web diagram shows a small proportion of the harmonies between the notes.

Notice how in the web diagrams above, the scale has a symmetrical pattern to it. Seeing harmony as a web of interconnections can help us design keyboards and other playing interfaces. This arrangement of notes is very different from the way notes are usually arranged on an instrument, which is in order of pitch in a one-dimensional row.

While it is important to know the order of pitch of the notes from low to high, the real beauty of harmony is its dimensionless quality, the way that notes link not to their immediate neighbors but branch out to various special points. A good keyboard should represent not only the linear order of pitches but also the dimensionless web of harmony. My keyboard uses colors to show a “harmonic web” superimposed on a linear scale of notes that are arranged in order of pitch.


You may think that my system looks complicated but it is tuned to simple frequency ratios, the same ones that have been used by musicians for thousands of years. They are so natural that I was able to tune them all by ear, and I’ve got a terrible sense of pitch, I can’t even sing Happy Birthday in tune.

Most musicians don’t understand the science of tuning and are unaware of just intonation, but to the ears the difference is obvious. Listen to two more of my sound files. You can hear something special in the sound even though I am not playing anything that special.



major scale


minor scale


I like to color code my notes to help me navigate around the keyboard by grouping related notes together with similar colors. My system is loosely based on the color wheel in and attempt to show emotional qualities of the intervals. It is not meant to be taken too literally as there is no literal relationship between colors and musical harmony, but there are some similarities.

It uses colors as a quick aid to remembering all the intervals and to help the musician build a mental map of a complex web of tonal possibilities. The symbolism I use is quite simple. A combination of three ideas.

  1. Warm/cold colors for sad/happy or major/minor notes e.g: orange-M3rd, purple-m3rd.
  2. Primary/secondary/tertiary colors for the range of dominant to obscure notes e.g: red-5th, purple-m3rd, brown-7:4.
  3. Complementary colors to show inverted pairs of notes e.g: 5th-red, 4th-green.Here are six fundamental intervals paired up with six points on the color wheel. Of course the associations are subjective, and in the right context they can be made to behave in the opposite way, (Yes, it’s possible to write a sad song using the major scale) but I think it is a good starting point.

Orange for M3rd — warmest color for the most important major interval
Blue for m6th — coldest color for the saddest interval
Red for 5th
Green appropriate for 4th because calm understated qualities
Yellow for M6th to me it is the sunniest interval used in a lot in Hawaiian music
Purple for m3rd sad with a touch of warmth, unlike m6th which is harsh and despairing




An string instrument or pipe has many modes of vibration that produce notes higher than the basic note to which it is tuned, and these notes form a scale of overtones, at multiples of the fundamental frequency. This scale is very natural and can be used to influence man-made scales. The harmonic series is closely related to the major scale and has a bright lively character.


overtones on piano The overtone scale can be inverted to make an undertone scale:

undertones350 undertones piano

The overtone scale can be inverted to make an undertone scale:

The undertone scale is less common in natural systems and has an opposite character to the overtone scale. It is related to the minor scale, but being a purer form of the minor scale it has a very dark, morbid character. The notes of the undertone scale get closer and closer together in the low end and therefore limit its useful range.

Using the overtone or undertone scale in their natural forms can be a bit limiting, but they are important to keep in mind when making music. I like to think of them as two opposite fundamental forces that define the character of music, like major vs minor, but more perfect. The traditional music theory explanation of major and minor scales is based on the circle of fifths and fourths, but I think that overtones and undertone are a more natural explanation.


Every interval has it’s own opposite apart from the octave and the tritone. The way to invert an interval is to play it descending from the root instead of ascending, e.g. play a 5th down from the root and you get a 4th in the octave below. One way to visualize this is to imagine a mirror placed at the root note.

Another way to make inversions is to reflect around the tritone. The tritone is exactly half way between two octaves. This way all our inversions say within the same octave that they came from.

Most intervals’ opposites are truly opposite in character and often don’t get placed in the same scale together, so musically they are not particularly useful and create a very atonal sound when played together, although they do give the whole system a nice symmetry, and the symmetry helps to simplify the visualization of a tuning system.


Dictionary of musical terms

“Just Intonation” is also referred to as “pure temperament”


“Instruments tuned to just intonation I find far more emotional to play.”

“I remember the first time I experimented with just intonation, it was an old electric organ that I re-tuned, I found the sound so captivating and beautiful, I suddenly found I could play away for hours improvising and really enjoying playing music, whereas before I would find it bland and uninspiring.”

“Just intonation could be seen by some as being a nerdy distraction from music making and and obscure pointless subject, but to me it is key to my enjoyment of playing a musical instrument and I want other people to experience its beauty.”

“Compared with equal temperament, the harmonies of just intonation sound purer, brighter and more defined.”

“The reason for using more than 12 notes is to allow for more freedom of movement.”

“This arrangement of notes is very different from the way notes are usually arranged on an instrument, which is in order of pitch in a one dimensional row.

While it is important to know the order of pitch of the notes from low to high, the real beauty of harmony is it’s dimensionless quality, the way that notes link not to their immediate neighbours but branch out to various special points.”

“A good keyboard should represent not only the linear order of pitches but also the dimensionless web of harmony.”