The Gospel organ of the Mexico city cathedral

## History

The gospel organ of Mexico cathedral was built by the organ builder José Nassarre in 1734-5 in Spain and imported to Mexico. This organ was used as a template to produce the twin but slightly smaller epistle organ, one of the most significant organs built in historical Mexico. The gospel organ is the singlehand largest and grandest authentic iberian style organ on the North American continent. It is also the largest 18th century organ in North America with 3 manuals and 57 stops. The organ was always kept in good condition, even after being damaged by a fire in 1967, where Flentrop made a restoration in 1978. The gospel organ was restored again by Gerhard Grenzing in 2008-09, followed by the epistle organ in 2014. Both organs are currently playable, and are even both tuned to A415 1/6th comma to play twin organ music together.

## Technical Details

The organ comprises of three manuals and pedals, with one of the manuals, the *solo,* is short compass and enclosed in a swell box. Like all Iberian organs, the two manuals of a full compass have a divided stop system. This allows a solo and accompaniment from one manual. The organ has two facades- one faced two the choir, another faced to the nave around it. The console is on the choir side, hidden by a small positif de dos. People suggest that hiding the console is this division's only real use, as a much more capable *Cadereta* division is installed is installed inside the organ case based on 8' pitch with mixtures and reeds, where as the external half has much less stops, based on 4' pitch with no reeds, but a solo cornet in the treble useful for solos or diallages with the two larger 7 rank cornets on the other manual. On the topic of the *Organo Mayor,* The division is rather capable, with a complete with a flautado plenum based on a increble 12 ranks of chorus mixture divided into 3 diffrent mixtures. In addition, there is a full flute plenum based on 8' complete with mutations and unique stops like the *Espigueta*, similar to a chimney flute. The reed department is rather undeveloped compared to both the flues and other Iberian organs. On the choir side, there is no 8' in the bass and no 4' in the treble. There is regal stops at 8' full compass and a 16' in the treble. There is also 3 sets of reeds including a regal mounted on the nave side façade. Of course there is a 8' trompeta real mounted vertically inside the organ case with the flue pipes. In the *Cadereta interior,* there is a bajoncillo/clarin, a split register that is 4' in the bass and 8' in the treble. These two stops are the only two ranks of reed pipes not mounted en chamade.

A uinque feature of this organ is the use of pneumatic action in the organ. The *Cadereta* and *Pedal* Both use pneumatic directly, via a pallet box mounted near the keys connected by a short tracker. The wind from this pallet box travels via tubes to the wind chests, where the wind is directed into into the key channels and the wind chest operates as a normal slider wind chest. Because there is no intermediate valve at the end of the pneumatic tubes, there is much less latency then all the other pneumatic actions made almost 200 years later, at the price of being heavy on the wind system to make sure there is enough availed to run the action. The solo manual, mounted next to the *Organo Mayor* at both the console and the wind chest, uses a tracker rollerboard to transfer the key movement across under the great wind chest and then transitions to pneumatic action. The *Organo Mayor* uses direct tracker action to the wind chest.

Interestingly, the pedal division stops can be played from the *Organo Mayor manual*. In the picture, one can see the end of the *Cadereta* manual *(note the missing low C#).* From here one can see the Or*gano Mayor's* manual has another octave added to that, missing C# and D#. this the the "pedal octave" and plays the pedal notes.

As mentioned above, the organ needs a strong wind system to supply large amounts of wind to both the pneumatic action system and the large 16' ranks, of whom there are 3 *(the wooden flatuado of the organo mayor, the open metal of the pedal contras in the facade, and the bajoncillo in the pedal, a reed)* as such, the organ is winded by 6 large wedge bellows, each with 6 folds, mounted above the pipework in the case. Above these there are two reservoirs of the wedge kind, but with 8 folds. There is also an electric blower for ease of use.

## Dispostion

**I. La Cadereta Exterior**

 Quincena
 Viente docena
 Diez y novena
 Corneta Magna

**I. La Cadereta Interior**

**II. Organo Mayor**

**III. Solo-Reactivo** *(C1-C5, expressive)*

 Docena
 Quincena
 Diez e novena
 Chirmia
 Violones

**Contras de Pedales** *(One octave minus C# & D#, can play from OM contra octave)*

 Contras
 Contras
 Bajonicllo
 Bajoncillo
 bajonicllo

**Registros de Adorno** *(effects controlled by tabs above the manuals)*

* Zimbelstern
* Bird whistle
* 2x Drum/thunder
* Giata (drone effect)