Online French Horn Tuner: The Complete Guide
The French horn is a transposing instrument, which means the note printed on your part isn't the pitch that actually comes out of the instrument. This tuner is built around that fact: it detects the true sounding pitch from your microphone, then shows you both what you'd read on your part and what's actually sounding, side by side, so tuning never gets confusing about which note is "correct."
How does this French horn tuner work?
This tuner uses the Web Audio API built into modern browsers to capture a short sample of sound from your microphone, then runs it through an autocorrelation algorithm. Autocorrelation compares a sound wave against slightly delayed copies of itself to find the point where the pattern repeats — that repeat rate is the true, physical sounding frequency of the note being played. From that concert pitch, the tuner applies your selected horn's transposition interval to calculate the written note name you'd see on a part, while all tuning accuracy (the cents reading) is always based on the real, physically measured concert pitch.
How to Use the French Horn Tuner
- Select your horn type — F or Bb — from the chips below the readout. F is the standard default for virtually all modern horn notation.
- Find a quiet space and tap "Start Tuner," allowing microphone access when your browser asks.
- Play a long, steady tone rather than a short articulated note, giving the pitch detector time to settle on a stable reading.
- Read the written note shown large at the top — this matches what you'd see on your part — with the true sounding concert pitch shown just below it.
- Watch the needle and cents reading, which are always based on the actual sounding pitch, to adjust your hand position, embouchure, or valve slides until the note reads in tune.
Transposition by Horn Type
"Transposition" describes the fixed interval between a written note and the pitch that actually sounds on a given instrument. These are the transpositions this tuner applies:
| Horn | Transposition | Written C Sounds As |
|---|---|---|
| Horn in F | Down a perfect 5th | F |
| Horn in Bb | Down a major 2nd | Bb |
Is French Horn Music Always Written in F?
By long-standing convention, almost always — yes. Modern horn players typically use a double horn with both an F side and a Bb side, switching between them (often automatically, via a trigger) depending on register for easier fingerings and better intonation in different parts of the range. Despite that, the written part itself is virtually always notated as if for a horn in F, regardless of which side of the instrument actually produces the sound at any given moment. This tuner's default "Horn in F" setting matches that near-universal notational convention; the "Horn in Bb" option is provided for the less common case of a part specifically written for Bb horn.
Why Show Both Written and Concert Pitch?
A horn player reading a part thinks in written pitch — that's the note they're fingering and the note a conductor or fellow musician will usually reference from the score. But the physical sound waves the tuner measures are the concert (sounding) pitch, which is what actually needs to match a reference like a piano or another instrument in tune. Showing both prevents the common confusion of a tuner "disagreeing" with a piano simply because one is reading written pitch and the other concert pitch — here, both are visible at once, correctly related to each other.
Common French Horn Tuning Problems (and How to Fix Them)
The tuner won't detect any sound
This almost always comes down to one of three things: microphone permission was denied, the page isn't loaded over a secure (https) connection, or your input volume is too low. Check your browser's site settings to confirm microphone access is allowed, and make sure no other tab or app is already using the microphone.
The horn reads consistently sharp or flat across the whole range
Check the main tuning slide first — pulling it out flattens the whole instrument, while pushing it in sharpens it. On a double horn, check whether the issue is present on both the F and Bb sides or only one, since each side has its own tuning slide.
Right-hand position is affecting the reading
Hand position inside the bell measurably affects a horn's pitch and tone color, more so than on most other brass instruments. If your reading seems to shift without changing anything else, check that your right-hand position in the bell is consistent with your normal playing position rather than an exaggerated or unusually loose stopping position.
Frequently Asked Questions
Is this online French horn tuner free to use?
Yes. This French horn tuner is completely free, runs in your browser, and does not require an account, download, or app install.
Why does the French horn tuner show two different note names?
The French horn is a transposing instrument, so the note printed on your part is not the same as the pitch that actually sounds. This tuner shows the written note, matching what you'd read on your part, alongside the concert pitch, which is the true sounding note measured directly from the audio.
Is French horn music always written for Horn in F?
By convention, yes, almost always. Even players using the Bb side of a modern double horn read the same F-transposed notation as F horn players, since horn parts are written in F by long-standing convention regardless of which side of the instrument actually produces the sound.
Why won't my French horn tuner detect sound?
Most commonly this happens because microphone permission was denied, the page is loaded over an insecure http connection instead of https, or background noise is too loud for the pitch detector to lock onto a single note.
Pitch detection runs entirely on your device — audio from your microphone is never recorded, stored, or sent to a server.