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Music Reference

440Hz Tuning Tone — Standard A4 Reference

The international standard for musical pitch. Pure, precise, and always available for tuning and calibration.

Free online tool · Works on mobile · No signup

How to Use This Tool

1

Click 'Play' to start the 440Hz reference tone

2

Adjust volume with the slider (start at 50%)

3

Tune your instrument's A string to match this pitch

4

Use Space bar to toggle playback on/off

440
Hz
Volume50%
Space: Play/Stop • ← →: Adjust frequency

Use Cases

What Will You Test?

Tuning

Tune to Concert Pitch

Before: Your orchestra tunes to A4=440Hz, but your tuner battery is dead.

After: Generate 440Hz instantly. Tune your A string to match. The whole orchestra can use the same reference.

Calibration

Calibrate Audio Equipment

Before: You need a known reference frequency to verify your audio interface is accurate.

After: 440Hz is the universal calibration standard. Generate it, measure it, confirm your gear is precise.

Education

Teach Pitch Standards

Before: Students don't understand what 'concert pitch' means in practice.

After: Play 440Hz. Explain this is A4, the reference all other notes are tuned from. Then show 432Hz to demonstrate pitch differences.

FAQ

Common Questions

Why is 440Hz the standard?
In 1955, the International Organization for Standardization (ISO) adopted A4=440Hz as the international standard for concert pitch. Most orchestras and instruments use this today.
What's the difference between 440Hz and 432Hz?
432Hz is approximately 8Hz lower than 440Hz. Some claim it sounds more 'natural' or 'relaxing,' but there's no scientific evidence. 440Hz remains the global standard.
Can I use this to tune a piano?
Yes, for a single reference note. But piano tuning requires adjusting for inharmonicity and temperament. Use this for a quick check, not a full piano tuning.
Do all orchestras use 440Hz?
Most do. Some European orchestras tune to 442Hz or 443Hz for a brighter sound. Always check what your ensemble uses.
Is 440Hz bad for you?
No. Claims that 440Hz causes stress or 432Hz has healing properties are pseudoscience. Both are simply different pitch standards with no proven health effects.

Start Testing Now

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