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Friday, 9 January 2004

Quick JJiCalc Tutorial

Launching JJiCalc

After you download the software to your computer, you can run it by double-clicking on JJiCalc.jar. Or, if you have a command prompt, you can type "java -jar JJiCalc.jar" .

Opening Files

Once the software is launched, click on the file menu and select open. A dialog box will come up listing files and directories on your computer. This box may look different from ones that you are used to. On OS X, the box will list files in the root directory. If you want to get to your home directory, click on the Users folder, then on your directory name. Go to the directory where you put the software. In the JJiCalc folder, there is a folder called tuning. Go there and open the file called old_grandad.jic

Eight tuning ratios will appear in the top of the tuning table. The title "Old Grandad" will appear in the title bar. (If you want to change the name, just type in the title field.) On the top right hand side of the application window are some buttons. One of them is called "Comments." If you click on comments, you can view the comments made about the scale.


Click the button marked "Lattice" to see the tuning lattice for the scale. A new window will pop up, which shows ratios connected by lines. If you want to hear a tuning ratio, you can click on it in the lattice. Click on 3/2. The box around the ratio will turn gray and you should hear the sound of the ratio being played. If you don't hear anything and you've made sure that sounds are working on your computer, you may need to update your Java libraries, especially Swing.

If you click again on the ratio, it will stop playing. You can play any number of ratios at the same time as you would like. Click on 3/2, 5/4 and 1/1.

Pop-up Menus

You can also play ratios directly from the tuning table. If you have a multi-button mouse, right click on the numerator or denominator of one of the ratios. If you are on a macintosh with a single-button mouse, option click on the numerator or denominator. A pop-up menu will appear with the options "Enable Sound", "Freeze this Cell", and "Clear this Cell". To hear the ratio, select "Enable Sound." To stop hearing the ratio, right or control click again and select "Disable Sound."

Frozen cells can't be played. Also, they can't be cleared and will not be sorted. To freeze a cell, right or control click on the cell for the pop-up menu. To defrost a cell, do the same thing again, but select "Defrost this Cell". To erase the contents of a cell and remove a ratio from the table, select "Clear this Cell".

Cents, Hertz, Fret Position

In the middle of the bottom of the application, there is a section of buttons labelled "View As." Click the one labelled "ET +-Cents". This will calculate the closest Equally Tempered pitches, plus or minus the cents needed to get your tuning. In the gray boxes below each ratio, you should see a postive or negative number indicating the cents to add or subtract, with the closest ET pitch below that. The JJiCalc assumes that 1/1 is C0, so therefore 5/4 is E0 -13.7 cents.

To calculate Hertz, click the button marked Hertz in the "View As" section. 1/1 defaults to 440. If you would like to use a different base frequency, on the bottom right is a section called "base frequency." Type in what frequency you would like in the text area marked "1/1 freq". Then, click the button "Update Base". If you play the ratios, they will sound at the new frequencies. The displayed Hertz will not change, however, until you click the "Hertz" button again in the "View As" area.

If you click the button "fret pos", it will calculate fret positions for you. The top number is the integer part of the fret position and the bottom number is the decimal section. Below 3/2, there is 0. in the top box and 3333 in the bottom box. Thus, for a string 1 meter long, the fret position for 3/2 would be at 0.3333 meters.

You can change the string length by typing it in the text area labelled "Str. Len." and then clicking the button labelled "string len". This will cause your fret positions to recompute. There is a known bug: The recomputed numbers will be incorrect. After you change the String Length, click the "fret pos" button again to figure out the correct fret positions.

Adding New Ratios

Go to an empty table cell and (left) click in the numerator box. type 15 and then in the denominator box, type 16. This adds a 15/16 minor second. If you click the lattice button, you will see your new fraction in the lattice.

The JJiCalc automatically reduces your fractions for you. In another empty cell, enter in 32/30. As soon as you click off of the cell, it will reduce to 16/15. There is an option under the Configuration menu to turn this reduction off. This is a known bug: Your fractions will always reduce.

The Configuration Menu

One thing that works in the configuration menu is changing the wave form setting. You can hear your fractions played as sine waves, square waves or sawtooth waves.


all of our tunings are in scale order except for the new one, 16/15. On the right is a button marked "Sort". Click it to but the ratios in order from smallest to largest.

All of the things in the gray boxes below the ratios will clear when you hit sort.


When you save your file, all of the data including the 1/1 frequency, the title, the comments, the ratios and the stuff written in the gray boxes below the ratios all get saved. Saving a tuning gives you the same kind of dialog box you got when you openned old_grandad.jic. If you type in the name of a file that already exists, a box will appear to ask if you're sure you want to overwrite the old file.

Other Formats

If you don't want to save anyhting but the title, the comments and the ratios (but not the stuff in the gray boxes), go to the File menu, then look in the Export submenu and select "Ratios only."

JJiCalc also supports the Scala file format. To save your tuning as a Scala file, select "Scala File" under the Export menu. There is a very large set of tunings in the Scala format that you can download from To open these tunings, select "Scala File" from the import menu. Not all Scala tunings are Just Intoned. If the Scala tuning that you open contains some non-just tunings, JJiCalc will approximate them as fractions.

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