Johann David Sieber - Baroque organ 1708 in Polná, Czech

The beautifully decorated church of Polná was built between 1700-08 according to the plans of the Italian architect Domenico d'Angeli under the patronage of Prince Leopold von Dietrichstein, the owner of the Polná region. The organ with 31 stops was delivered in 1708 by Johann David Sieber (ca. 1670-1723, the best Moravian organ builder of the 18th century. He could manufacture larger instruments than his competitors (up to about 40 stops on three manuals) and was known for the quality of his craftsmanship and technical inventiveness. The Sieber organ for Polná was his fourth largest instrument and it was perfectly preserved in original form to this day. Jürgen Ahrend studied the Polná instrument carefully during the reconstruction of the Sieber organ in Vienna (1986-87). Polná's organists remember that Ahrend restored the resonators of the pedal trumpet in Polná in gratitude for the research he was able to do there.

The organ was expertly overhauled in 2017 by a consortium of Czech organ building companies, MgA. Dalibor Michek, Dlabal Mettler and MgA. Marek Vorlíček. The organ was transported to the various organ workshops. The case of the instrument remained in Polná, and was restored by Jan Mach. The organ was affected by worms, but that was restored to its original design. The organ originally had a fifth comma tuning and that was maintained. The keyboards are still the original Sieber keyboards, which is really unique for an organ of this age. They are among the oldest surviving keyboards. The wind supply was restored to its original state: four large chip bellows in the church tower. In this way Polná has an original Czech Baroque organ in the style of 1708.

The organ of Polná is a two-manual instrument with 31 stops. The upper manual is the Hauptwerk with 16 stops. Its typical feature is the complete pyramid of the Principal choir, crowned with a Mixtur and a Cymbel in high position. The plenum of czech (south German) instruments is completely different in character from that of the North German plena. The character is strongly determined by the registers in high foot sizes, they give the organ a clear, transparent sound. As a contrast to the Principals, the Hauptwerk has Flute Voices with a clear but subdued intonation. In addition, two soft strings with a specific sound. Together they form the typical elements of the Czech Baroque organ.

The Gamba has the sound of a conical flute and can be used as a replacement for a Gedackt 8'. The lower manual is the Positiv with eight stops, typically designed as the little brother of the Hauptwerk. Here too, the main choir is built up to the highest tones, so that the highest location is added to the sounds when linking to the Hauptwerk. The Pedal is intended to support the final chords of the music. It includes only 12 chromatic tones (the lowest octave), although the pedal keyboard has 18 keys, common for Czech baroque instruments. Although reeds were extremely rare on Czech baroque instruments, the pedal of the Polná instrument offers two: a Schnarrbas 16' with wooden resonators and a Trumpet bass 8'.

Copula major       8'
Principal              4'
Copula minor       4'
Nassatquinte       3'
Octava                2'
Quinta           1 1/2'
Superoctava         1'
Mixtura         IV fach

Bourdonflöte        16'
Principal               8'
Quintadena          8'
Gamba                8'
Salecinal             8'
Octava                4'
Nachthorn            4'
Fugara                 4'
Quinta                 3'
Superoctava         2' 
Feldflet                2'
Quintadecima  1 1/2'
Seddecima           1'
Mixtuur        V fach
Cimbel        III fach
Subbass               16'
Subbass Clausus    16'
Octavbass              8'
Quintbass              6' Superoctavbass      4'
Schnarrbass          16'
Trompetbass          8'
Rich sounds of Czech baroque

The pipes made by Johann David Sieber are of particularly good quality and testify to great craftsmanship. The scales he calculated for the entire pipework in combination with his excellent art of subtly voicing, shows the master who has experience with the construction of large and sound-rich organs.

Characteristic of the sound of this organ are the singing-rich registers. Clear voices, audible everywhere in the acoustics of the church, but never sharp. This applies to the Principals as well as to the Strings and Flutes. The plenum of Principalen is constructed, as in the Italian Ripieno, by making the individual registers up to a pipe length of 1 foot. More than the organs that can be found in northern areas, the emphasis is on color. Sounds of registers with the same foot size, subtly differ in character and can be mixed in many combinations into new colors. This Czech organ by Sieber adds a wide color palette, which is not surpassed by any organ.

The Cimbels, as well as the Mixture of the Positive, can form a plenum of high composition. They are good to use as a solo voice together with the flutes and aliquots. The tonal effect of the flute registers is lively, colorful and full. The sound of the Schnarrbass is powerful, that of the Trumpet is clear, without sounding shrill.

During my visits to Czech organs I have become acquainted with the special style of the sounds, but never have I found so much in one organ. The sounds are carefully and evenly stored in the samples and perfectly reflect the enormous richness of sound.

The sample set of Sonus Paradisi in unique; there is no set that adds so many new sounds on the Hauptwerk organ, all with their own musical value.
                                                                                                         Sonus Paradisi