“Each pipe speaks. It has a body, a foot and a soul: tuning is not only a physical process, it requires artistic evaluation and sensitivity.”
Intonation is the process that determines the timbre, the colour of the sound propagated, the voice of the pipe that speaks. The ancient instrument of the Cathedral counts 15,800 pipes, with reed pipes and flue pipes that assume different behaviours. They have to be aligned and constantly maintained harmonious. However, seasonal ordinary maintenance does not suffice for the Organ of the Duomo. In fact, it is subjected to progressive organic deterioration because it is made of living materials, such as wood, metal and leather. Exposed to the considerable movement of abrasive marble powder that deposits with debris and particulate on the pipes, obstructing them, the instrument is subjected to considerable stress, such as, for instance, laceration of Rélais leather that creates an asthmatic sound due to the absence of wind (air).
Hence, a public competition will be shortly launched to start renovation works on its mechanical parts by 31 October. However, it must absolutely include also the renovation of the organ cases and of the precious wooden parts that is currently in progress at the Quartana restoration Studio.
Here, at the workshop, we find all the parts of the low choir, tiles and caryatids, ready to be cleaned and renovated, restored to the original varnish that was concealed by a faux layer of dark colour applied during the mannerist period on replaced parts, not on the reverse side, and on broken parts to disguise reconstructed parts. The tiles are cleaned with laser technology because it is healthy for the operator and gentle on the object. It avoids the use of solvents and can be calibrated. Indeed, the power of the laser is variable. Always starting from a diffuser, which is also used for gilding, various lenses are tested, reaching the convergent one, which is the most powerful. The beam allows to clean the undercuts by thermal ablation, vaporising the material to be removed, such as oils and waxes applied during previous maintenance, without heating the object. Mechanical finishing touches on engravings with surgical knife, tweezers and sponges are only performed at the end.
Instead, impurities are removed from the caryatids by using a mixture of non-aggressive and odourless gel to remove the wax and the dark colour without damaging the original varnish. Finishes are then applied with the laser.
They will both be protected and polished with a wax obtained by processing the honeycomb and authorised by the Superintendence. They are not photosensitive synthetic waxes that detach from the wood, causing the paint to darken but are, instead, natural waxes that still have the scent of honey.
Finally, the renovation of the wooden parts envisages a new system to reassemble the tiles and caryatids, based on reversibility criteria. The original screws shall be replaced with stainless steel screws that will be isolated from the wood with either grease or rubber to diminish temperature changes that would create condensate and the subsequent attack of fungi and insects. Fiberglass screws, specially studied for the Duomo, are an alternative to stainless steel screws. The iron brackets and cases that seal the tiles will be replaced by spring steel.
This is only the first step towards completing the renovation of the largest Organ in Italy and one of the first ten largest organs in the world, a masterpiece of expert craftsmanship. It will, once again, sing magnificently with the support of all those who wish to contribute to the fund collection campaign “15,800 notes for Duomo di Milano”.
Become a donor and you will receive invitations for concerts at the Cathedral and for many other initiatives scheduled for the new cultural season 2019/2020. Thank you!