Justly

Important

Requires dependencies on Linux. To install, run sudo apt install fluidsynth qt6-base-dev qt6-gtk-platformtheme qt6-wayland.

Important

Requires dependencies on MacOS. To install, run brew install fluid-synth qt.

Installation

You can download binaries for Justly here. The Justly executable is in the "bin" subfolder.

Motivation

You can use Justly to both compose and play music using any pitches you want. Using staff notation, you can only write the pitched notes of the 12-tone scale. Some intervals in any 12-tone scale are close to harmonic, but other intervals are not. Johnston expanded staff notation, but relying on staff notation limited him.

Notation

Ratios

In Justly, you write ratios as a a rational fraction (integer / integer). Justly will omit the numerator if it is 1, and omit the denominator if it is 1. Therefore:

• "" represents the ratio 1
• "/2" represents the ratio $\frac{1}{2}$

Intervals

In Justly, you write intervals as a rational fraction (integer / integer) times a power of 2. An "o" suffix is a short hand for "*2^", similar to how the "e" suffix is shorthand for "*10^".

Justly will omit the numerator if it is 1, the denominator if it is 1, and the octave if it is 0. Therefore:

• "" represents the interval 1
• "/3" represents the interval $\frac{1}{3}$
• "o1" represents the interval $2^1$
• "/3o1" represents the interval $\frac{1}{3}*2^1$

You will likely only need to know 4 "prime" intervals.

• Octave: 2
• Perfect fifth: $\frac{3}{2}$
• Major third: $\frac{5}{4}$
• Harmonic seventh: $\frac{7}{4}$

Note that the numerators of these fractions are the first 4 prime numbers.

To go up by an interval, multiply by the interval. So to go up by a fifth, multiply by $\frac{3}{2}$.

To go down instead of up, divide by the interval. So to go down by a fifth, divide by $\frac{3}{2}$ = multiply by $\frac{2}{3}$.

You can write the same interval in multiple ways. For example, you can write a fifth as $\frac{3}{2}$, or "3o-1" = $\frac{3}{1}*2^{-1}$.

You can create new intervals by multiplying and dividing intervals. For example, a minor third is up a perfect fifth and down a major third: $\frac{3}{2} \div \frac{5}{4} = \frac{6}{5}$.

Here are some useful composite intervals:

• Major second: $\frac{9}{8}$ = perfect fifth * perfect fifth / octave
• Minor third: $\frac{6}{5}$ = perfect fifth / major third
• Perfect fourth: $\frac{4}{3}$ = octave / perfect fifth
• Minor sixth: $\frac{8}{5}$ = octave / major third
• Major sixth: $\frac{5}{3}$ = octave / perfect fifth * major third
• Minor seventh: $\frac{9}{5}$ = perfect fifth * perfect fifth / major third
• Major seventh: $\frac{15}{8}$ = perfect fifth * major third

I suggest using a rational calculator to multiply and divide intervals.

Gain vs. velocity

In Justly, there are two kinds of volume: "gain", which is the speaker volume, and "velocity", the force with which Justly plays a note. You can adjust the gain of the whole song, or the velocity of different notes.

Starting values

• "Gain" is the gain, between 0 and 10.
• "Starting key" is the starting key, in Hz. For reference, see the piano key frequencies on Wikipedia.
• "Starting velocity" is the starting velocity, between 0 and 127.
• "Starting tempo" is the starting tempo, in beats per minute (bpm).

Instruments

You can use any of the instruments included with MuseScore soundfont.

Chords, pitched notes, and unpitched notes

A chord is a set of pitched and unpitched notes that begin playing simulataneously.

Chords have the following fields, each corresponding to a column:

• "Instrument": If not empty, Justly changes the default instrument for pitched notes to this (see below).
• "Percussion set": If not empty, Justly changes the default percussion set for unpitched notes to this (see below).
• "Percussion instrument": If not empty, Justly changes the default percussion instrument for unpitched notes to this (see below).
• "Interval": Justly multiplies the current key by this ratio. Changing the interval of a chord changes the key of all future chords.
• "Beats": The number of beats until the next chord starts
• "Velocity ratio": Justly multiplies the current velocity by this ratio. Changing the velocity ratio of a chord changes the velocity of all future chords.
• "Tempo ratio": Justly multiplies the current tempo by this ratio. Changing the tempo ratio of a chord changes the tempo of all future chords.
• "Words": text associated with the chord
• "Pitched notes": the number of pitched notes in the chord
• "Unpitched notes": the number of unpitched notes in the chord

Both pitched and unpitched notes both have the following fields:

• "Beats": When Justly startings the chord, Justly will play the note ifor this this number of beats.
• "Velocity ratio": Justly sets the note velocity to the current velocity times this ratio. Changing the velocity ratio of a note does not change the current velocity.
• "Words": text associated with the note.

Pitched notes have the following additional fields.

• "Instrument": The instrument of the pitched note. If empty, Justly will use the default instrument for the chord (see above).
• "Interval": Justly sets the note's pitch to this interval times the current key. Changing the interval of a pitched note does not change the current velocity.

On the other hand, unpitched notes have the following additional fields.

• "Percussion set": The percussion set of the unpitched note. If empty, Justly will use the default percussion set for the chord (see above).
• "Percussion instrument": The percussion instrument of the unpitched note. If empty, Justly will use the default percussion instrument for the chord (see above).

Interface

Controls

You can edit the gain, starting key, starting velocity, and starting tempo using the controls on the left.

Table editor

Each row of the table represents a unit: a chord, pitched note, or unpitched note.

You can select a single cell by clicking on it. Hold shift to select multiple cells. When you select a chord or pitched note cell, Justly will show corresponding frequency and approximate piano key in the status bar at the bottom.

To edit the pitched notes of a chord, double click its "Pitched notes" cell. To edit the unpitched notes of a chord, double click its "Unpitched notes" cell. To go back to the chords, select "Back to chords" from the "Edit" menu (see below).

File Menu

In the "File" menu, you can choose among the following options:

• "Open" to open a previously saved song.
• "Save" to save the song in the previous location.
• "Save As" to save the song in a new location.
• "Export recording" to export a recording of the song as a wav file.

Edit Menu

In the "Edit" menu, you can choose among the following options:

• "Undo" to undo any action.
• "Redo" to redo any action.
• "Cut" to cut a selected group of cells.
• "Copy" to copy a selected group of cells.
• "Paste" to choose among the following:
  • "Over" to paste over the selected cells.
  • "Into start" to paste rows into the start of the table.
  • "After" to paste rows after the selected cells.
• "Insert" to choose among the following:
  • "After" to insert a row after the selected cells.
  • "Into start" to insert a row into the start of the table.
• "Delete cells" to delete cell contents.
• "Remove rows" to remove selected rows.

View Menu

In the "View" menu, you can choose among the following options:

• Check/uncheck "Controls" to view/hide the controls, respectively.

Play Menu

In the play menu, you can choose among the following options:

• "Play selection" to play a selection of chords or notes. If you play a selection of chords, you will skip any previous chords, and only play the selected chords. If you play a selection of notes within a chord, you will skip any previous chords, and only play the selected notes within the current chord.
• "Stop Playing" to stop playing.

Example

This example is the simple.json file in the examples folder.

Here is screenshot of the chords in the song:

The song starts with a key of frequency 220Hz, that is, A3.

In the first chord, Justly sets the default instrument to Grand Piano. The key does not change in the first chord.

After 1 beat, the key changes: Justly divides the key by $\frac{3}{2}$, so the key goes down by a fifth. Now, the key is close to D4.

After 1 more beat, Justly multiplies the key by $\frac{3}{2}$, so the key goes up by a fifth. Now, the key is back to A3.

Here is a screenshot of the pitched notes in the first chord:

The pitched notes in the first chord are the tonic (≈A3), third (≈C#4), and fifth (≈E4).

Here is a screenshot of the pitched notes in the second chord:

The pitched notes in the second chord are the fifth (≈A3), up 1 octave (≈D4), and up 1 octave and a third (≈F#4).

Here is a screenshot of the pitched notes in the third chord:

The pitched notes in the third chord are the tonic (≈A3), third (≈C#4), and fifth (≈E4).