Prof Gerhard Walterskirchen, musicologist. Back in 1628, when the cathedral was consecrated, two ‘well adorned organs’ were installed in the eastern dome pillars. After 1640, when the cathedral was furnished, organs were also installed in the western domes – small, single manual pieces that were intended for continuo practice and piano playing.
In accordance with the polychoral style practised in Northern Italy, two organs were generally played: Girolamo Diruta, Claudio Merulo and Andrea Gabrieli, along with other important organists of their time, composed music for St Mark’s in Venice, where two organs were used since the late 15th century. Music composed for two organs also became the style in the cathedral in Milan and north of the Alps.
Despite a lack of music written for two organs in the Salzburg Cathedral music archive: the traditional ‘Canzoni per ogni sorte d’instrumenti’ give clear reference to this particularly attractive sounding music.
Towards the late 17th century, the two east pipe organs in the cathedral were rebuilt into two-manual organs: the ‘Hoforgel’ to the right of the altar was given 14 registers, while the opposite organ, the ‘Heilig Geist-Orgel’ (Holy Ghost organ) was given 13 stops. The ‘Hoforgel’ was played by important court organists such as Carl van Houven († 1661), Georg Muffat (1678-1690), Johann Ernst Eberlin (1726-1749), Anton Cajetan Adlgasser (1750-1777), W. A. Mozart (1779-1781) and Johann Michael Haydn (1782-1806).
They left behind pieces for liturgical and concert performances, some included the organ as a concert instrument in their mass and vespers compositions - W. A. Mozart, for example, in his ‘Organ Solo Mass’ KV 259, his Vesper KV 321 and his church sonatas; Michael Haydn in at least thirty of his church compositions. Despite this, the baroque galleries and organs were removed during renovations in 1859. In 1988, master organ builder, Johann Pirchner, from Steinach/Tyrol was commissioned to rebuild the two east dome organs. They were to be reconstructed as purely mechanical two-manual instruments, however the larger of the two organs should also be suitable as a choir organ for congregational singing and therefore have a manual range from C - d3 and a pedal range from C - d1. The opposite organ was to be equipped with a manual and pedal with a short, large octave. Both works have 14 registers and two manuals and pedals.