As adults, we don’t think all that much about the fall board on our pianos other than to cover the keys when we’re not playing and, if we’re honest about it, most of us only close it to keep the cat from playing raucously at 4 in the morning.
As adults with children, we know that at some point there will be more than one child at the piano and that they will argue over who gets to play or what they will play together. The argument will escalate to the point where one of them shuts the piano on the other. Many older pianos would have allowed that argument to end in the emergency room with a smashed hand and splinted fingers.
The soft close on this Hailun piano means you get to correct their argument without a medical emergency.
Just about every piano can play mezzo forte or mf. It’s not all that difficult to get a piano to sound as loud as the resonant body will allow. It’s all in the power you can put behind the articulation. The challenge with a piano is creating a soft, intimate sound.
Particularly with vertical style pianos, we must create enough space for the hammer to fall away from the strings. This is the point of “let-off.” If the hammer doesn’t let-off then it blocks against the string producing only the sound of impact. The inverse problem of let-off is if the hammer falls away too early so that it must traverse the distance by the force of momentum- this forces the musician to put more force into the note just to guarantee the note is heard which results in louder playing. The ideal position for let-off to occur is as close to the strings as possible allowing for seasonal changes in humidity, humidity which can warp the wooden rails ever so slightly but more than enough to change let-off.
One of my customers has an instrument where either the quality of the wood or the grain alignment is so incredibly responsive to humidity change that I have to adjust let-off regularly throughout the year so that they are able to make music. In one season there’s far too much left to inertia that it only plays loudly, so it gets adjusted, the next season he finds the hammers creating that percussive blocking sound.
There is another option of course, don’t use wood! I service many pianos where the wooden rail has been replaced with aluminum. Problem solved? Nearly. the let-off buttons are threaded like a screw, also made of metal. Metal isn’t susceptible to humidity changes but it is susceptible to temperature change. In the Southeastern Pennsylvania Summer we are very fond of air-conditioning which shrinks the screw and the aluminum rail. The holes don’t shrink, they expand because the metal shrinks away which under extreme situation can generate a clicking sound but mostly just allows the regulating screws to change position.
The most reliable way to maintain let-off at the closest point possible is to marry the two materials- quality wood rail fit perfectly inside an aluminum U-channel. The aluminum prevents the wood from warping during humidity change and the wood holds the regulation screws nicely through temperature change.
This allows for very stable regulating, liberating your piano technician to comfortably place let-off much closer to the strings. What this means for the performer is that you can always be sure that your most delicate repertoire will sing in the whisper it deserves.
The smaller a piano, the more attention to detail and precision is needed.
Many upright pianos and even some grand pianos use only the cast iron plate as a termination point for the speaking length of a piano wire. That particular metal is very hard and brittle which does well enough for enhancing the bright timbre of a note but can be unforgiving when you’re trying to achieve a deep, dark tone.
Lower pitches are achieved with longer and heavier wire – there’s so much weight and therefore more energy to generate the volume required that balance is easier to achieve with a softer metal. The softer metal absorbs some of the brightness and the bass bridge should provide enough motion for the lower vibrations to speak beautifully. On the Hailun upright, the termination point near the tuning pins has a uniform cut-off because the angle of the string to that termination point is set within the agraffe and not by how far the tuning pins are driven into the pin-block.
As you move to the tenor section the strings are linked bearing down on the bridge where the soundboard is the widest across the grain. This allows for more energy to be evenly distributed through the soundboard (acoustic membrane). Here we achieve uniform down-bearing with a capo bar – the same is true in the treble. On most pianos the cast iron forms the termination point, but on the Hailun the tenor section has a brass rail which can be replaced if ever needed. The fact that the rail is brass means that it is a much softer termination point for the tenor and it also is a larger diameter than the treble, this helps to support those singing tones we love so much in the mid-range.
The treble section has a similar design to the tenor with one important change: The termination rail is made of stainless steel and is a smaller diameter. This gives the higher notes more precision and support for clear tone projection. The shorter the strings get, the more precise all our measurements need to be- the length, weight, and hammer strike-point can make or break an entire piano in the high treble.