Parts of a Bassoon – Reed, Bocal, Joints, Boot and Bell

All 12 parts on the diagram

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Reed and bocal 2

Reed A double reed. Its two blades vibrate against each other.
Bocal A thin curved metal tube from the reed to the wing joint.

Joints 6

Wing joint Runs from the boot up to the bocal. Also called tenor joint.
Bass joint The long joint that links the boot to the bell.
Boot The bottom joint. The bore turns back up inside it.
Bell The top joint, where the long folded tube ends.
U-tube A metal bend that joins the boot's two bores into one tube.
Boot cap A metal cap that covers and protects the U-tube.

Keys, holes and hand rest 4

Whisper key Held with the left thumb on low notes to stop cracking.
Tone holes Open holes in the body. Fingers cover them to change the note.
Keys Levers with pads that close holes the fingers cannot reach.
Hand rest The right hand leans on it. Also called a crutch.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two independent sources use it for this part. (1) Wikipedia, text only: Bassoon (its six main pieces: reed, bocal or crook, wing joint or tenor joint, boot or butt, bass joint or long joint, bell; the U-shaped metal connector in the boot, tone holes, key work, the whisper key, the hand rest or crutch), https://en.wikipedia.org/wiki/Bassoon . (2) An instrument maker's online Musical Instrument Guide, The Structure of the Bassoon (reed, bocal, tenor joint, double joint, bass joint, bell, tone holes, the U-tube and its protector cap), https://www.yamaha.com/en/musical_instrument_guide/bassoon/mechanism/ . (3) Clayton H. Tiede, The Practical Band Instrument Repair Manual (1970), searched in full text at https://archive.org/details/practicalbandins00tied (reed, bocal, tenor or wing joint, boot or butt joint, bass joint, bell, whisper key and the small hole in the bocal, hand rest, boot cap, tone holes). (4) Anthony Baines, Woodwind Instruments and Their History, searched in full text at https://archive.org/details/woodwindinstrume00bain (crook, wing or tenor joint, double joint or butt, bass or long joint, bell, hand-rest, the metal U-tube at the bottom of the butt). (5) Julius Weissenborn, Method for Bassoon, searched in full text at https://archive.org/details/methodforbassoon0000weis (crook, wing or tenor joint, boot, long joint, bell, sound holes). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's instrument, nothing traced. Licence: own work

How it works

A bassoon comes apart into six pieces: reed, bocal, wing joint, boot, bass joint and bell. Follow the air down the wing joint, around the bottom of the boot and up to the bell.

Read the full guide

Two views, whole and boot

Numbers 1 to 7 are the whole bassoon: reed, bocal, wing joint, bass joint, boot, bell and the whisper key. Numbers 8 to 12 are on the boot: tone holes, keys, the hand rest, and at the foot the U-tube and the boot cap.

A long tube bent double

The bore runs down from the bocal through the wing joint, turns in the U-tube at the foot of the boot, and climbs through the bass joint to the bell. Unfolded, the tube would be about twice as long as the bassoon is tall.

Some joints have two names: wing joint or tenor joint, bass joint or long joint, boot or butt, bocal or crook.

Questions and answers

What are the main parts of a bassoon?

Six pieces: the reed, the bocal, the wing joint, the boot, the bass joint and the bell. The wood joints carry the tone holes and the keys.

What is the bocal on a bassoon?

A thin, curved metal tube, also called the crook. The reed fits on its narrow end, and its other end plugs into the top of the wing joint.

What does the boot of a bassoon do?

It is the bottom joint. It has two bores side by side, joined at the foot by a metal U-tube, so the air comes down one side and goes back up the other.

What is the whisper key for?

Its small pad covers a tiny hole in the bocal. The player holds it with the left thumb on low notes, which keeps them from cracking up into a higher octave.