frequency

The frequency property defines the pitch of a note in Hertz (Hz).

Default Value

440  // A4 (concert pitch)

Expression Examples

Fixed Frequency

440     // A4
261     // ~C4
880     // A5

Relative to BaseNote

// Same as BaseNote
base.f

// Perfect fifth above (3:2 ratio)
base.f * (3/2)

// Octave above (2:1 ratio)
base.f * 2

// Perfect fourth below
base.f / (4/3)

Legacy JavaScript syntax

module.baseNote.getVariable('frequency')
module.baseNote.getVariable('frequency').mul(new Fraction(3, 2))
module.baseNote.getVariable('frequency').mul(new Fraction(2))
module.baseNote.getVariable('frequency').div(new Fraction(4, 3))

Relative to Another Note

// Major third above Note 1
[1].f * (5/4)

// Octave below Note 3
[3].f / 2

Legacy JavaScript syntax

module.getNoteById(1).getVariable('frequency').mul(new Fraction(5, 4))
module.getNoteById(3).getVariable('frequency').div(new Fraction(2))

TET (Equal Temperament)

// 12-TET semitone
base.f * 2 ^ (1/12)

// 12-TET major third (4 semitones)
base.f * 2 ^ (4/12)

// 19-TET step
base.f * 2 ^ (1/19)

Legacy JavaScript syntax

module.baseNote.getVariable('frequency').mul(new Fraction(2).pow(new Fraction(1, 12)))
module.baseNote.getVariable('frequency').mul(new Fraction(2).pow(new Fraction(4, 12)))
module.baseNote.getVariable('frequency').mul(new Fraction(2).pow(new Fraction(1, 19)))

Irrational Frequencies

TET frequencies are irrational and display with the ≈ prefix. RMT Compose preserves their algebraic form using SymbolicPower.

Common Just Intonation Ratios

Interval	Ratio	DSL Expression
Unison	1/1	base.f
Minor second	16/15	base.f * (16/15)
Major second	9/8	base.f * (9/8)
Minor third	6/5	base.f * (6/5)
Major third	5/4	base.f * (5/4)
Perfect fourth	4/3	base.f * (4/3)
Tritone	45/32	base.f * (45/32)
Perfect fifth	3/2	base.f * (3/2)
Minor sixth	8/5	base.f * (8/5)
Major sixth	5/3	base.f * (5/3)
Minor seventh	9/5	base.f * (9/5)
Major seventh	15/8	base.f * (15/8)
Octave	2/1	base.f * 2

Visualization

• Vertical position on the workspace represents frequency
• Higher frequencies appear higher on screen
• The Y-axis uses logarithmic scaling: log2(baseFreq / freq) * 100
• Dashed lines indicate octave boundaries

Audio Playback

During playback, the frequency value (converted to a JavaScript number) is used to set the oscillator frequency. For irrational frequencies (TET), the floating-point approximation is used.

Dependencies

When a note's frequency references another note, a dependency is created:

// Note 2 depends on Note 1's frequency
[1].f * (3/2)

Changing Note 1's frequency will automatically update Note 2.

See Also

• Pure Ratios - Just intonation theory
• Equal Temperament - TET systems
• Expression Syntax - Full syntax reference