Some of the most common left-hand “failures

Any leakage originating in the left hand is often of spectacular proportions. In fact, the higher up the bore it is, the more it invalidates the whole instrument. Take, for example, a clogging problem in the octave keys. If they don’t plug, nothing works. In fact, it’s their signature. Why would they not plug?

1st octave

The first octave, for example, depends on the relationship between the left thumb keys on the underside of the instrument (orange arrow in photo below). Occasionally, the third octave key can be pressed too hard against the first, keeping it perpetually open.   There are two solutions: simply move the two keys apart a little by hand, so that they don’t touch, even when the third key is used on its own. Don’t overdo it, or they’ll break! The other is to lightly screw in the screw in number 2 on the photo below. Be careful not to overdo it, otherwise the first octave won’t lift enough. If it does, do as you would for a crush, and manually move the 3rd octave key a little away from the first. Then simply stop pressing like a blacksmith on the third octave, and the problem will disappear forever.

                                                                                  –                   1                     2

If the problem only arises in pairs, with the second octave unable to close the first sufficiently, it’s because the adjustment screw between the two (no. 1 above) needs to be strengthened a little to allow the first octave to tip up onto the crown of the case and close properly. On the other hand, another scenario may prevent it from rising, making octaviation impossible: If you’ve disassembled your octave keys for spring cleaning, and on reassembly the spring (orange arrow in the photo below) which holds the first octave key has not been correctly positioned underneath it, it locks in the closed position. There’s no need to get worked up – it won’t go back up until the spring’s back in place!

2nd octave

In the case of the second octave, as this key operates by direct pressure of the left index finger, it’s never the opening that poses a problem, but the closing. There are two most likely possibilities: the cork is cracked or diseased and leaking, and needs changing. If the cigarette-paper test shows the plug to be loose, there’s something wrong with the spring or stem. Has the spring turned, is it on the right side of its hook (to force the key to close), and is it strong enough to do so? If, from the spring’s point of view, everything seems fine, remove the stem and check that it’s in good condition and that the key hasn’t seized up. If this is the case, there may have been torsion, impact, rust or simply a lack of oil. This last hypothesis is the most likely in most cases. Solving the problem is well within our capabilities. Refer to the blog on tools, where I mention the type of oil to use. Other slightly less invasive but nonetheless very frequent and disruptive problems have their source in the balance of the direct and indirect keys of the left hand fingers.

Left-hand adjustment protocol

A very simple but essential protocol for a perfect result must be observed: any key pressed with the finger has priority over the others. Its nearest neighbor comes second, and so on the further you move away from the “epicenter” of the pressure. This is particularly important when adjusting the G and A fingers. In the passive state, i.e. without any action on our part, the small intermediate keys, n°2 and 4 below, are closed.

–                                                                                    –                                                                                     4      3       2         1

But as soon as the right index finger comes into play, (to play a Bb for example) these same small keys are released and owe their closing only to the G and A fingers. According to the above-mentioned law of priority, it is essential to ensure that no preference is given to a key other than the one pressed with the finger. To be sure, I recommend preventively unscrewing the adjustment screw at the junction point between the G key and the A resonance (no. 1 in the photo below). As the screw slot acts as an hour hand, simply move it back 30 minutes. This way, it won’t interfere with the setting protocol. If you wish to make this adjustment with only the upper body in your hands, press the index finger of your left hand against the yellow arrow on the stem in n°2. This leaves the thumb of the same hand free to act on the G and A keys.

                                                                                                –                                                                                                  –                            1                            2

Start with A and its resonance. Screw n°1 in the image below is responsible for this adjustment. If the resonance is too low, turn it clockwise until it’s balanced. It may only be a few seconds on the “clockwise dial”. If you have to press too hard on the La finger, it’s the other way round and you’ll have to turn it “a tad” to the left. Using cigarette paper (the “cold” method) or while playing (the “hot” method), check the balance between the two. They should be almost equal, with one finger almost imperceptibly favored over its neighbor. With paper, the difference should be almost zero. It must resist identically without slipping under the pads with normal finger pressure. Playing only with the upper body, while “disengaging” the resonances with the thumb of the right hand on the rod in no. 2 of the image above, we press with a finger of the right hand on the middle finger of the left or on the resonance key. There should be no difference in sound or color quality.

                                                                                                                –                      1                             2                                           3

Then we move on to G. This finger is responsible for the blocking of two indirect keys: its resonance and that of A, whose relationship we deliberately removed two paragraphs above. Start by making the same observation and adjustment as for the A, with screw n°3 responsible for the relationship of the G and its resonance. When the balance is established between the two, and only then, can we deal with its correspondence with that of A. The case where the G finger is responsible for closing this small, indirect and “more distant” key is interesting. For this, we need to play a left-handed fork. What’s the only time this happens? Yes, for the G-sharp! It’s on this fork that these two keys must be adjusted, either hot or cold. As screw n°2 has been unscrewed by 30 minutes, it’s a safe bet that the A resonance will be low. Just as well. The opposite would be totally disruptive to the tuning, with any attempt at balance becoming impossible for the G and its neighbor. We therefore need to gradually return to equilibrium by turning this screw n°2 clockwise for 20 to 25 minutes and checking. This ratio should be in favor of the left ring finger. The cigarette paper must obviously be tighter under the G finger than under the A resonance. However, attacking the G-sharp should not be difficult due to the weakness of the setting. When warm, it’s very easy to realize this and find the perfect balance for yourself and your individual way of pressing the keys. On paper, give a distinct advantage to the G, which should never be at a disadvantage in terms of tightening compared to the small wrench. When this is the case – and it happens more often than you think – adjusting the left hand turns out to be a headache of the Chinese kind, with no solution!