An octave below the bassoon, and near the floor of the dial
A contrabassoon reads in bass clef exactly like a bassoon and sounds one octave lower. Because the gap is a pure octave, the note letter a concert-pitch tuner names is already the letter on your part — only the octave number differs. There is nothing to convert and no transposition setting to reach for.
What makes this the hardest instrument on this site to read is not the notation but the physics. The bottom of the range is concert B♭0 at 29.14 Hz — the lowest note in the orchestra, and low enough that whether your microphone can hear it at all is a real question rather than a rhetorical one.
Concert pitch in the tone, written note in the label. The bottom row is 29 Hz — most laptop speakers will not reproduce it, and headphones may not either.
It has a tuning slide, and that is the surprise
A bassoonist arriving here brings one strong rule with them: never pull the bocal. On a bassoon that is exactly right, because the bocal carries the whisper-key vent and pulling it moves the vent away from its pad — the bassoon page explains that in full.
A contrabassoon is built differently. It generally has a proper tuning slide, a mechanism whose only job is to change the length of the instrument, and using it is correct rather than damaging. So the rule inverts: reach for the slide first, and treat the reed as the fine adjustment rather than the only one.
The routine
- Warm it for longer than feels necessary. Around five metres of tubing has to reach a stable temperature, and the instrument drifts sharp the whole time it is doing so. Ten minutes is not excessive before a performance.
- Play written A4 and look for concert A3, 220 Hz. Mezzo-forte, steady, reading from the middle of the note.
- Sharp: pull the tuning slide out. Flat: push it in. If your instrument has no slide, the reed is the adjustment — and it is a much smaller one.
- Hold low notes two to three seconds before believing the dial. Watch the octave display: if a written C3 reads two octaves above where you expect, the tuner has locked onto a harmonic rather than the fundamental.
- Check the octaves across the break. This is where a leak or a badly adjusted whisper key shows up as the low register going flat while the middle stays put.
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 contrabassoon sounds an octave lower than it reads, so written C comes out as concert C an octave down.
That gap is a pure octave, so the note letter on the dial is already the one on your part — only the octave digit beside it differs. There is nothing to switch: read the letter, ignore the number, and the two agree.
The low end of the ensemble
Three instruments on this site regularly work below 60 Hz, and they share one practical problem: the fundamental is weak, slow to establish, and easy for a microphone to miss.
- Contrabassoon — down to concert B♭0, 29.14 Hz. The lowest here.
- Tuba — the pedal register, which most tuners decline to name at all.
- Double bass — E1 at 41.20 Hz, with a C extension reaching lower still.
The dial on this page reads down to 20 Hz, which is what makes checking the bottom of a contrabassoon possible at all — but your microphone is the limiting factor, not the software. On the double-reed side, the bassoon and english horn pages cover the reed-and-bocal questions this one takes for granted.