he fact that it has two keyboards and 26 spans contras (pedals), with 22 stops on the left hand and 25 on the right hand, places it among the main Castilian instruments of the 18th century, being one of the biggest, with the exception of the ones in cathedrals.
In terms of structure, the most innovative feature of La Seca organ is the extended octave. It is the first time that this feature is used in the province of Valladolid, even though it had been used years before by other organ-builders.
It is worth highlighting the quality of the “machine”, the great presence of the exterior horizontal reeds and some exotic details such as the Trompeta Universal of 52 spans (32′) on the right hand, not present in other Castilian organs.
Its composition reveals a taste for adornment stops, with a variety of soloist stops and a focus on the spectacular nature of the reeds. The 26 spans contras highlight the purpose of this organ as a great organ considering the time and place.
The interior cadereta is not an “echo organ”, which was common back then, and can be considered a positive organ.
It is very large and neoclassical, with some Baroque reminiscences. It is located in the tribune on the north side.
It is made of pine wood, with marbled polychromy and golden carvings and moldings.
Both the key action and the stop action are located in the lower section, as well as the whole cadereta. This section is dummy originally, without “ears” to let the sound out.
The great organ (órgano mayor) and the contras (pedals) are located in the upper section.
Measurements: 7.50 m high, 5.8 m wide and 1.6 m deep.
The complexity of its mechanical structure, which is very large and has numerous channel boards arranged in an intricate framework, reveals a high-quality design and constructive technique with a very developed practice skillfully carried out, which favors flawless conservation of the wood and all other elements.
The wind chests are made of pine wood and the sliders are made of walnut:
- O.M. (great organ): large chromatic wind chest in two sections; 20 middle stops with channel boards.
- Cadereta (low organ): chromatic wind chest built in one section; 5 middle stops with channel boards.
It has two mounted small wind-chests, above the main wind chest, for the cornetas and nazardos and for the echo stops.
Tree-shaped wrought iron stop action and forks at the head of the sliders.
- O.M. (great organ): keyboard with shaft at the rear end of the key, as was customary; roller board.
- Cadereta: backfall keyboard and valves on the upper side of the wind chest, therefore it has tracker action with backfalls; roller board.
Almost all the pipe work is made of metal, except for the three basses of the flautado of the cadereta, the concert flute and the 26 spans contras (pedals). It is 95% original. Tradicional workmanship with 50% tin-lead alloy and lead languids.
One wedge bellows, not original, where there was a system of small pumps actioned by a wheel and a crankshaft. It is possible that the current boards were the bellows’ original ones.
Harmonization and tuning
- Harmonization at 62 mm wc
- Tuning pitch 415 Hz at 18º
- Temperament: modified meantone
It has preserved most of its essence, despite having undergone some reforms. Except for the modification of the tuning pitch and the loss of a small part of the pipe work, it has maintained its mechanical elements and the sounding material entirely, without stylistic modifications, in spite of its two hundred years of history and some poor quality works.