Part of Vivaldi Studio · iPad & Mac

Vivaldi Keyboard

An 88-key piano with twenty-two historical temperaments and twenty-one transposing instruments. Hear what your alto sax actually plays. Tune your harpsichord in 1/4-comma meantone. Compare Equal Temperament against Pythagorean, in cents, in real time.

Made for musicians, theory teachers, tuners, and historical-tuning nerds. We dare you to find this elsewhere.

Vivaldi Keyboard — control wheels and 88-key piano

What it does

Three control wheels, an 88-key piano, and the math underneath. That's the whole app — and it's enough.

22 Temperaments

Equal, Just Intonation, Meantone, Well Temperaments, Historical reconstructions, Pythagorean, World scales. Switch with a turn of the wheel.

21 Transposing Instruments

Saxes, clarinets, brass, strings, woodwinds — verified MIDI ranges and correct octave transposition. The keyboard dims keys outside your instrument's range.

Concert Pitch, for real

Play a written C on Alto Sax, hear the actual E♭ concert at the temperament's exact frequency. No mental math, no approximation.

Cent Deviations Panel

See the exact offset of every note from Equal Temperament. Open the ¢ tab and watch the math.

Variable Reference Note

For non-equal temperaments, choose which key is pure. Shift the wolf, find the sweet spots.

SoundFont + Bank Selection

Import any .sf2 from Files or iCloud. The app parses every preset inside — melodic banks, drum kits, dozens of instruments — and lets you pick from a scrollable preset list. Swap presets live while you play.

All 22 Temperaments

Seven categories. Each comes with a description in the in-app guide — what it sounds like, where it came from, why it matters.

Regular

Equal (12-TET)

Just Intonation

5-limit7-limit

Meantone

1/4 comma1/3 comma1/5 comma1/6 comma2/7 comma

Well Temperament

Werckmeister IIIKirnberger IIIVallottiYoungNeidhardtBarnes

Historical

Bach / LehmanRameauKellner

Pythagorean

Pythagorean

World / Extended

19-TET31-TET53-TETArabic 24-TET

Transposing Instruments

Twenty-one instruments with verified MIDI ranges and correct octave transposition. Pick your instrument from the wheel and the keyboard reshapes itself: keys outside the playable range dim out, frequencies shift to match your concert pitch.

Play a written C on alto sax → you hear the actual concert E♭, at the exact frequency of the selected temperament. No conversion in your head. Ever.

Woodwinds Piccolo, Flute, Oboe, Clarinet E♭, Clarinet B♭, Bassoon
Saxes Soprano B♭, Alto E♭, Tenor B♭, Baritone E♭
Brass Trumpet B♭, Trumpet C, Horn in F, Trombone, Tuba, Flugelhorn B♭
Strings Violin, Viola, Cello, Double Bass

Twenty-one transposing instruments plus Concert pitch. Real ranges, real transposition.

Sounds

Five built-in instruments from a bundled 142 MB FluidR3 GM SoundFont, plus any .sf2 you import. Multi-touch polyphony on iPad, click-to-play on Mac.

Piano

Acoustic grand — warm, full-bodied, the default starting point.

Organ

Church organ — deep, sustained; pairs well with well-temperaments.

Flute

GM flute — clean, single-voice; perfect for hearing temperament differences.

Strings

String ensemble — sustained legato, great for hearing beating intervals.

Harpsichord

Percussive attack, brittle overtones; made for historical temperaments.

Need more? The SoundFont + Bank Selection pillar above covers custom .sf2 imports with live preset switching.

Reference Frequency

Configurable from 415 Hz (baroque pitch) to 466 Hz (high orchestral). Default is the modern A = 440 Hz.

Frequency updates instantly while you play. Pair it with a meantone temperament and suddenly you're rehearsing on a real harpsichord — without owning one.

A4 range
415 Hz 440 Hz 466 Hz

How it works

Three wheels above, an 88-key piano below, a reference-pitch slider alongside. That's the whole interface.

1

Transpose & instrument

Turn the Transpose wheel, then pick your exact instrument from the rail that appears.

2

See your range

Keys outside the instrument's playable range dim out. You still see them, but you know.

3

Temperament

Choose a category on the Temperament wheel. For non-equal tunings, a Root Note rail appears to pick which key is pure.

4

Sound

Piano, organ, flute, strings, harpsichord — or any .sf2 with live preset switching.

5

Play

88 keys. Multi-touch on iPad, click on Mac. Hold the left-edge circle: one finger drags to scroll, two fingers drag up or down to zoom.

Frequency calculation

MIDI note touched
+ concertPitchOffset (from selected instrument)
= concert MIDI note

baseFreq = referenceFreq × 2^((midiConcert − 69) / 12)
+ cent offset from temperament
= final frequency

Two gestures, one circle

A single hold circle on the left edge. One finger drags to scroll the 88 keys. Two fingers drag vertically to zoom in and out. No menus, no toolbars.

Hold the left-edge circle, one finger drags to scroll.
Hold the left-edge circle, two fingers drag up or down to zoom.

Three wheels, 88 keys, landscape only.

Tutorials

Two short walk-throughs of the workflow and the SoundFont import. Videos coming soon — meanwhile, here is what each one will show.

Video coming soon

From silence to music

Tutorial 1

From silence to music

The five-step workflow, start to finish. What the video will show:

  1. Turn the Transpose wheel — the instrument rail lights up.
  2. Pick an instrument (say, Alto Sax in E♭).
  3. Watch the keyboard dim keys outside the playable range.
  4. Turn the Temperament wheel — pick 1/4 comma meantone.
  5. Play a chord. Hear the beatless thirds.

Video coming soon

Bring your own sound

Tutorial 2

Bring your own sound

Import any .sf2 and pick the preset. What the video will show:

  1. Turn the Sound wheel to Custom.
  2. Tap the import button — Files app opens.
  3. Pick any .sf2 file (iCloud, Downloads, wherever).
  4. The app parses every preset inside — melodic banks, drum kits, dozens of instruments.
  5. Pick a preset from the list. Play. Swap to a different preset while still holding notes.

One purchase. iPad and Mac.

Universal Purchase: buy once, play on iPad and Mac. No subscription, no telemetry, no account.

€1.99 — coming soon to the App Store.

Support & Contact