Tests 4, 5, 6, and Appendix

The keywork for the lowest notes on the bassoon are often out of adjustment causing leaks that greatly effect tuning and response. A simple leak test for the long joint is to remove the joint from the bassoon, place the large opening against the calf of your leg, close the Low B key (C and D keys should also close with it), and blow air into the small end of the long joint tenon. It should hold the air against your breath. It will be obvious if air is escaping as you will hear the sound.

Most pad heights can be temporarily adjusted with ordinary paper folded in layers as needed. The exception are the normally-closed tone hole notes which will require “sticky” note paper to hold in place. These will need to be built up in layers. These include the following notes:

  • Low Db (cork key stop may be missing)
  • Low Eb (cork key stop may be missing)
  • F# (rocker key from the F touch may be missing cork or felt)
  • Ab
  • Bb

Photos coming soon!

Low C and D Pad Closure

When the Low C key is touched by itself, the Low D pad should be completely closed. This will require either the adjustment of the lever in Fig. 7C or shims under the pad stop for D. The lever should be bent upward. Care should be taken that the C key closes properly.

Photo coming soon!

In some cases the Low D pad is closed, touching the Low C, but the Low C will not close completely without undue pressure on the C touch. This will require adjustment of the lever of Low C, bending it downward away from the C touch.

Low B Pad Closure

Touching the Low B key should completely close Low D, C, and B. If touching the Low B key by itself does not close all keys completely, shims will be required below the B touch and/or the Low B pad lever.


  • Tone hole
  • Touch points
  • Keys
  • Pad Height

How to lower the pad height (pitch) for Low B

Add paper shims on the bridge key that closes the Low B tone hole.

How to lower the pad height (pitch) for Low C

Lower the pad height at the key stop lever.

How to lower the pad height (pitch) for Low Db and Eb

Add sticky shims under the key’s cork or felt.

How to lower the pad height (pitch) for Low D

Add paper shims under the Low B key thumb touch point (in between the key and Low C touch/above the pad cup).

How to lower the pad height (pitch) for Low E

Add shims between the Low D key lever and pad stop.