A French horn’s transposition, a trumpet’s fingerings
A mellophone is in F, reads treble clef, and sounds a perfect fifth below the written note — the same transposition a French horn player already lives with. Written C comes out as concert F4 at 349.23 Hz, and when the band tunes to concert B♭, your note is written F.
The trap is that everything else is different. A mellophone is fingered far closer to a trumpet than to a horn, so the horn player moved onto one for marching season reads familiar notes and presses unfamiliar valves. And the bell points forward, which takes away the one correction a horn player relies on most.
Concert pitch in the tone, written note in the label. The highlighted row is the open landmark to set the main slide against.
No hand in the bell means the slide has to be right
On a French horn, the right hand sits inside the bell and adjusts the pitch continuously — it is not a rescue technique, it is how the instrument is played, and it is why horn players can tolerate an instrument that is not perfectly set. A bell-front mellophone removes that entirely.
The consequence is straightforward and it is the single most useful thing on this page: on a mellophone, whatever the main tuning slide is wrong by is what the audience hears. There is no continuous correction happening in the background. That makes a tuner more useful here than on a horn, not less.
The routine
- Warm the instrument through, at the temperature you will perform in. Five minutes of playing.
- Play open written C — the fourth partial, concert F4 — mezzo-forte. Without lipping it into place; let it sit where the instrument puts it.
- Sharp: pull the main slide out. Flat: push it in.
- Check written F, your concert B♭. This is the note the whole ensemble will actually tune on, so confirm it after the main slide is set rather than tuning on it directly.
- Check the valve combinations. As on any valved brass instrument, 1–3 and 1–2–3 run sharp because each valve’s tubing is cut to be correct alone rather than stacked. Learn how far out on your horn, since you cannot correct it with a hand.
Make the dial read your written note instead
Everything above names the concert pitch actually in the air, which is what a tuner is for and what the rest of the ensemble hears. But it is not what is printed on your part: a F mellophone sounds a perfect fifth lower than it reads, so written C comes out as concert F.
This tuner can close that gap for you. The Transposition setting adds the interval back before the note is named, so the dial reports the note you are reading rather than the note you are sounding — the one thing a guitar tuner has no reason to do, and the reason to keep this page rather than the first tuner in the results.
Open this tuner set to F → — or reach it yourself from the gear icon on the dial, under Transposition. The choice is remembered on this device and it travels in the link, so a section leader can send that URL to a stand full of mellophones and everyone arrives set the same way.
Switch it back to C — Concert pitch whenever you need to check yourself against the room, tune to a piano, or find out what a written note is actually sounding.
The F instruments
Two instruments on this site are in F and read treble clef, and they transpose identically while behaving nothing alike:
| Instrument | Written C sounds | Pitch correction available |
|---|---|---|
| French horn | concert F, a 5th lower | hand in the bell, continuously |
| Mellophone (this page) | concert F, a 5th lower | the slide, and your lip |
The english horn is also in F, on the double-reed side, and takes the same Transposition setting for the same reason. If you are covering trumpet parts on this horn, the trumpet page has the valve-combination arithmetic in full.