Sounding Circle
A music theory workbench for sound healers. Hear every key, chord and interval, see it under your hands on the piano, and carry it across to handpan and Native flute.
Now sounding
C major
Scale
Range and hands
Pace
Keyboard and fingering
Chords in C major
The seven chords the key builds on its own degrees. Roman numerals in capitals are major, lowercase minor, ° diminished, + augmented. Tap one to hear it; change the key on the Circle tab.
Chord chart
Tap a note on the clock to set the root, then tap the middle to play it. The shape drawn between the notes is the chord — the same shape slides round the clock unchanged whatever root you build on.
Arrow keys move the root and the quality. Space plays.
Quality
The whole grid
All twelve notes down the side, seven moods across the top. Tap any cell to hear it and load it into the clock above. Tap a note at the left to run across that row and hear one starting note change mood; tap a heading to run down that column and hear one mood move through every key.
Intervals
The distance between two notes, measured in half steps. Tap any row to hear it — first one note after the other, then both together. The ratio is the just-intonation ideal; equal temperament bends most of them slightly so every key works.
| Interval | Half steps | From root | Ratio | Character |
|---|
Press play and name what you hear
Every question starts on a different note, so you are naming the distance rather than the pitch.
Handpan scales
A handpan is built to one scale and cannot be retuned, so the scale is the instrument. The centre note is the ding; the notes around it are the tone fields, ascending as they alternate side to side. Tap the diagram to play, or play the whole layout.
Layout
Makers vary, and two pans with the same scale name can differ by a note. Always check the layout stamped on your own instrument.
Shruti box
A box of free reeds with no keyboard — you open the stops you want and pump, and they sound until you close them. One uniform row of sliders, as on the instrument itself. The sliders latch: tap one to open a reed, tap it again to close it. Dark faces are the sharp notes, so the pattern shifts as you move Sa. The usual drone is Sa and Pa, the tonic and the fifth.
Sa sits on
Common drones
Silent. Tap a stop to open a reed.
Lowercase names are the komal (flattened) swaras and Ma′ is tivra Ma, the raised fourth. The gold-ringed sliders are Sa, and the bellows breathes while any reed is open. Switching between 432 and 440 in the sound bar slides the open reeds to the new pitch rather than restarting them, so you can hear the drone move.
Native American flute
The six-hole flute plays a minor pentatonic scale with one standard fingering pattern, so the same six shapes work in every key. Filled circles are covered holes; open circles are uncovered. The third hole from the top stays covered throughout this run.
Everything above the sixth shape — the half holes and cross fingerings that give the other notes — varies by maker, so follow the chart that came with your flute.
432 or 440
A tuning standard is just an agreement about where one note sits; everything else is measured from it. The switch in the sound bar moves this whole app between the two, so you can hear the difference on any scale, chord or instrument here.
Played together they beat about 8 times a second — the difference between the two frequencies. That wobble is the whole gap, and it is what you would hear from two instruments in a room tuned differently.
| A = 440 Hz | A = 432 Hz | |
|---|---|---|
| Reference A above middle C | 440.00 Hz | 432.00 Hz |
| Middle C | 261.63 Hz | 256.87 Hz |
| Distance from 440 | — | 31.8 cents flat |
| As a share of a half step | — | about one third |
| Status | ISO 16, the international reference | A deliberate alternative |
Where 440 came from. Pitch standards have wandered for centuries. France set 435 Hz in the 1860s, British piano tuners used 439, and the American music industry settled informally on 440 by 1926. Delegates meeting in London agreed on 440 in May 1939, and the ISO adopted it in 1955, formalising it as ISO 16 in 1975. Even now it is not universal: much of continental Europe tunes between 440 and 444, and early-music ensembles drop to 415.
Where 432 came from. Verdi argued for lowering the French standard slightly, mostly to ease the strain on singers, and A = 432 is still promoted as “Verdi tuning.” A separate idea, scientific pitch, sets middle C at exactly 256 Hz so that every C is a power of two; that puts A near 430.5, not 432.
Claims that 432 Hz has healing properties, or matches the earth’s resonance, are not supported by evidence, and some of the stories told alongside them are flatly false. What is real is that people often describe a lower tuning as warmer or easier to sing over, and that is reason enough to choose it if you prefer it.
What actually matters in a session. Agreement. A handpan cast at 440 and a flute cut for 432 will beat against each other no matter how either one was chosen. Fixed-pitch instruments — handpan, bowls, chimes, most flutes — cannot be moved once made, so decide the standard before you buy, and keep a set together.