Sun Tone (Cousto’s construction)

126.22 Hz

Nearest note: B2, 38 cents above standard tuning

A tone Hans Cousto constructs for the Sun. It is not a measurement of anything the Sun does.

How well is this supported?

DerivedIdea, not a measurement

Calculated from a measured value by a stated method. You can check the arithmetic. What the result means is a matter of interpretation.

Cousto constructs this tone from an imagined orbit. It does not come from a cycle that was measured, and nothing the Sun does makes this sound.

What the four labels meanChecked against sources September 27, 2026

Compare with another tone

The button plays a plain tone. Start with the volume low. Phone and laptop speakers play low notes quietly; headphones or a speaker help.

Where this number comes from

This is not the rotation of the Sun. Cousto defines a Sun tone from an imagined orbit at the gravitational length of the Sun, 1.476 km, travelled at the speed of light. That gives 32,312.52 Hz. Eight octaves down is 126.22 Hz, a B about 38 cents above standard tuning. It is a construction, not a measurement of anything the Sun does.

Step 1. Start with Cousto’s figure
Cousto presents the Sun tone as a limit value derived from an imagined orbit at the Sun’s gravitational length, not as the Sun’s equatorial rotation period. Original tone at octave 0: 32,312.52 Hz.
Step 2. Halve it 8 times
Halving a frequency lowers it by one octave. After 8 halvings it is 126.22 Hz.
Step 3. Name the note
126.22 Hz is a B, 38 cents above standard tuning. A cent is one hundredth of the step between two neighboring piano keys. To play in tune with this tone, an instrument sets its A to 449.80 Hz instead of 440.
Step 4. Keep doubling and the number lands in the range of light
42 more doublings give the frequency of light with a wavelength of 540 nm, which is yellow-green. This is arithmetic. It pairs a tone with a color; it does not show that the two are connected.

The method is Hans Cousto’s. Planet gongs explained walks through it and says what it does and does not show.

Facts

Frequency: 126.22 Hz
Wavelength in air (20 °C): 2.72 m
Nearest note: B2, 38 cents above standard tuning
Kind of statement: Idea, not a measurement
Filed under: Earth, Moon & Sun

Tuning Data

The row for this tone in Hans Cousto’s tables, with the tempo and pendulum length that follow from it.

Cycle: Cousto solar tone limit value
Starting tone: Original tone at octave 0: 32,312.52 Hz
Octaves down: 8
Concert pitch (A): 449.80 Hz
Difference from A = 440 Hz: +38.13 cents
Tempo: 118.33 beats per minute
Pendulum length: 6.4 cm / 2.52 in
Color by octave: Yellow-Green (540 nm)

Tempo and pendulum length, octave by octave

Octave	Frequency	One cycle	Tempo	Pendulum
-14tempo	1.97 Hz	507.05 ms	118.33 BPM	6.4 cm
-13	3.94 Hz	253.53 ms	236.66 BPM	1.6 cm
-12	7.89 Hz	126.76 ms	Too fast to count	Too short to build
-11	15.78 Hz	63.38 ms	Too fast to count	Too short to build
-10	31.56 Hz	31.69 ms	Too fast to count	Too short to build
-9	63.11 Hz	15.85 ms	Too fast to count	Too short to build
-8tone	126.22 Hz	7.92 ms	Too fast to count	Too short to build

Intervals built on this tone

Ratio	Interval	Frequency	Note	Concert A	Cents from 440
1/1	Perfect unison	126.22 Hz	B2	449.80 Hz	+38.12
81/80	Syntonic comma	127.80 Hz	C3	429.86 Hz	-40.37
531441/524288	Pythagorean comma	127.94 Hz	C3	430.34 Hz	-38.42
128/125	Diesis	129.25 Hz	C3	434.74 Hz	-20.82
648/625	Greater diesis	130.86 Hz	C3	440.18 Hz	+0.69
25/24	Chroma	131.48 Hz	C3	442.24 Hz	+8.80
16/15	Diatonic semitone	134.63 Hz	C3	452.86 Hz	+49.86
10/9	Minor whole tone	140.24 Hz	C#3	445.25 Hz	+20.53
9/8	Major whole tone	142.00 Hz	C#3	450.81 Hz	+42.03
8/7	Septimal whole tone	144.25 Hz	D3	432.27 Hz	-30.70
6/5	Minor third	151.46 Hz	D#3	428.40 Hz	-46.23
5/4	Major third	157.78 Hz	D#3	446.26 Hz	+24.44
4/3	Perfect fourth	168.29 Hz	E3	449.29 Hz	+36.17
3/2	Perfect fifth	189.33 Hz	F#3	450.31 Hz	+40.08
8/5	Minor sixth	201.95 Hz	G#3	427.92 Hz	-48.19
5/3	Major sixth	210.37 Hz	G#3	445.75 Hz	+22.48
7/4	Natural seventh	220.89 Hz	A3	441.77 Hz	+6.95
16/9	Pythagorean minor seventh	224.39 Hz	A3	448.78 Hz	+34.21
9/5	Just minor seventh	227.20 Hz	A#3	428.89 Hz	-44.28
15/8	Major seventh	236.66 Hz	A#3	446.76 Hz	+26.39
2/1	Octave	252.44 Hz	B3	449.80 Hz	+38.12

Source notes

Cousto presents the Sun tone as a limit value derived from an imagined orbit at the Sun’s gravitational length, not as the Sun’s equatorial rotation period.

Source: Hans Cousto — Tuning Data / Sun Earth Moon Planets. View the source PDF, page 41.

License: CC BY-NC-ND 4.0, as stated in Stimmdaten.pdf (German edition), page 2.

Values are reproduced from Cousto’s tables. Tempo, pendulum length and interval tables are calculated by this site from those values.

See every tone in the tables: Open the tuning data reference.

Sources

Hans Cousto — Tuning Data: Earth, Moon, Planets, Sun
The tables that the tuning pages on this site reproduce.
Hans Cousto, Tuning Data — Earth Moon Planets Sun. Planetware.
View source: Hans Cousto — Tuning Data: Earth, Moon, Planets, Sun
Hans Cousto — Tuning Data / Sun Earth Moon Planets — Sun Tone
Cousto presents the Sun tone as a limit value derived from an imagined orbit at the Sun’s gravitational length, not as the Sun’s equatorial rotation period.
View source: Hans Cousto — Tuning Data / Sun Earth Moon Planets — Sun Tone

More about the pitch

The same note in every octave

Each step doubles or halves the frequency. Tap one to hear it.

Entries close in pitch

Within 35 cents of this tone, in any octave. A cent is one hundredth of the step between two neighboring piano keys. Being close in pitch does not mean two things are connected.

Related entries

Solar Cycle (11-year)Measured2.90 × 10⁻⁹ Hz