Polaron.de Apps Overview Napo / Virtual Organ Apps de en

Zell ET / MT

App Version: 1.4
Napo Version: 4.23

released 2019-02-25

Audiobus Compatible

About the Apps

Zell ET ("Equal Temperament") and Zell MT ("Meantone Temperament") are two iOS applications which allow you to play the sample sets of the Christian Zell harpsichord of the Museu de la Música de Barcelona on a MIDI keyboard connected to your iOS device. Both apps are based on the Napo framework. Please read the Napo documentation and in particular the Napo user manual to learn about its features and limitations.

Furthermore, there is an app bundle with Zell ET and Zell MT for the same price as a single app. So if you purchase one of the apps, you can later by "bundle completion" download the other one for free. If you would like to use only one of the apps, you need to download only that one and thus can save storage space on the device.

Zell ET Zell MT Zell ET + Zell MT

Originally, Napo is tailored for organ instruments. Therefore the following remarks:

It should be noted that Zell ET is retuned to 440 Hz while Zell MT is based on 415 Hz like the original instrument. This can be changed with the pitch setting of the apps.

As Zell ET and Zell MT have the same user interface, for easier discrimination of both apps the letters "ET" or "MT" are displayed at the left bottom:

In the versions 1.1 of the apps we have spread the stops to two manuals and added a coupler. Even though the real instrument has only one manual, and elsewhere we are rather reluctant to add elements that are not present at the original, we did not want to forgo this simple means to increase the musical versatility.

As it is common for harpsichord with two manuals, the lower manual now carries 8', 4' and lute stop, the upper manual the other 8'. The lower manual can be coupled to the upper manual. The stops knobs at the screen are arranged according to their affiliation to the manuals.

Starting with version 1.3, the note range of Zell ET is extended from C - d3 to FF - f3. The needed sound data was created from existing sound material by using "simple pitch shifting" of the Wavosaur program. The concerned MIDI note numbers:

Usedto create
36 C 29 F
37 C#30 F#
38 D 31 G
39 D#32 G#
40 E 33 A
41 F 34 A#
42 F#35 B
84 C 87 D#
85 C#88 E
86 D 89 F

About the Sample Sets

The sample sets which underly both apps were recorded by Pere Casulleras and members of the Museu de la Música de Barcelona as well as the Escola Superior de Música de Catalunya. Because of the complicated acoustical circumstances and the constructional conditions in the museum (e.g. a continuously running air conditioning system) this was a quite challenging and time-consuming process. Think of the fact that the very long fade-out sound of each single note was recorded, and also the sounds at key release. In spite of these circumstances, and due to faithful postprocessing, sample sets have resulted that deliver a realistic impression of the instrument and are a great pleasure to make music with. Using the version adapted to equal temperament, a large range of keyboard pieces can be played, but the meantone original has its own charm as well.

The sample sets are freely available at http://samplesets.esmuc.info resp. http://casacota.cat and can for example be used with GrandOrgue as well. We would like to express our thankfulness to the creators for giving permission to incorporate the WAV files in our apps, and also to the museum for maintaining and caring for this beautiful instrument.

About the Harpsichord

According to Wikipedia, three instruments of the Hamburg harpsichord builder Christian Zell have survived, one from 1728, one from 1737 and one from 1741. The instrument in the Museu de la Música de Barcelona is the 1737 harpsichord and has the following sounds:

Name Notes
8' I C-d3
8' II C-d3
4' C-d3
Lute Stop affects 8' I

The picture in the Gallery view of the apps, which shows the 1737 harpsichord at its exhibition place in the museum and served as a base for the app icons and for the app store artwork, is from the Wikipedia article. In the MIMO (musical instrument museums online) there is another nice photo. We used this photo when we crafted the background picture of the apps' Console views.

Sound Examples

With thanks to Andreas Lesch:

Composition ET/MT M4A
Johann Sebastian Bach: Prelude in C major, BWV 924 (from the Twelve Little Preludes) ET 6.2 MB
Wolfgang Amadeus Mozart: Sonata No. 11 A major, KV 331, first movement, theme ET 13.1 MB
Wolfgang Amadeus Mozart: Sonata No. 11 A major, KV 331, first movement, Var. IV ET 17.8 MB
Christian Petzold / J.S. Bach: Menuet in G major, BWV Anh. 114 (Notebook Anna Magdalena Bach) MT 8.4 MB
Christian Petzold / J.S. Bach: Menuet in G minor, BWV Anh. 115 (Notebook for Anna Magdalena Bach) MT 8.7 MB
Jeremiah Clarke: The Prince of Denmark's March MT 20.2 MB
Johann Sebastian Bach: Theme from the Goldberg Variations, BWV 988 MT 19 MB
Georg Friedrich Händel: Lascia ch’io pianga, aria from the opera Rinaldo ET 10.8 MB
In dieser Nacht (Gotteslob Nr. 91) ET 3.9 MB
J.S. Bach: Prelude in F major, BWV 927 (from the Klavierbüchlein für Wilhelm Friedemann Bach) ET 4.9 MB

Demo Videos

Composition Link
William Edmund, Jigg in G Minor YouTube
thesoundtestroom: App-Review YouTube