Tuning Fork A440 - Diapason

Diapason Plus – Your guide to musical tuning

A simple and reliable app

Diapason Plus is the perfect app for musicians, choir conductors, and music enthusiasts.
With its clear and intuitive interface, it gives you quick and accurate access to the most common reference frequencies: 440 Hz, 432 Hz, 415 Hz, and a custom frequency.
Whether you’re tuning an instrument or finding the right pitch for a choir, Diapason Plus is the essential tool to guarantee perfect intonation in any situation.

Why choose Diapason Plus?

Music requires precision and speed.
Diapason Plus offers both, with a minimal and functional design that lets you focus entirely on your music.
Perfect for rehearsals, concerts, lessons, or personal study.

• Ease of use: select the desired frequency with a tap or choose a custom value.


• Speed: activate the tuning fork instantly, with no complications.


• Precision: standard frequencies calibrated for professionals and enthusiasts alike.

The three preset frequencies and their uses

440 Hz – The standard A

This is the universally recognized frequency for tuning musical instruments.
Known as the “International A”, it is the modern standard, providing a clear and stable reference for intonation.

432 Hz – A historical alternative

The 432 Hz is sometimes used as an alternative to 440 Hz.
Some musicians prefer it for its slightly lower pitch, often perceived as softer and warmer.
While not an official standard, it is appreciated for the unique expressiveness it offers.

415 Hz – The baroque choice

About a semitone below 440 Hz, 415 Hz is typical of baroque and early music.
It offers an authentic intonation faithful to historical context, making it ideal for instruments such as harpsichords and baroque violins.

Custom frequency and duration

With Diapason Plus you’re not limited to preset values: you can freely choose a tuning frequency within a dedicated range.
Sound duration is fixed in the basic version, while in the Pro version it becomes adjustable, giving you greater control to suit your musical needs.

Extra features

• Shake to Play: shake your smartphone to instantly start the tuning fork, no buttons needed. (Available only on devices with the required gyroscope sensors.)


• Keep screen on: prevent the display from turning off while using the app.


• Tap to stop: tap the tuning fork while it’s playing to stop the sound immediately.

Pro version

With Diapason Plus Pro you get even more:

• Extended frequency range from 50 Hz to 2100 Hz.


• Adjustable tone duration from 2 to 10 seconds.


• Exclusive interface with a golden tuning fork.


• Completely ad-free experience.

Simplicity and precision

Diapason Plus lets you easily switch between preset frequencies or select a custom value.
Its accuracy makes it perfect for choir conductors, music teachers, and anyone in need of a stable reference tone.
Whatever your musical context, Diapason Plus will help you achieve perfect intonation.

Note: the sound quality and actual frequency range may vary depending on the hardware capabilities of your device.