After 1945 Fokker continued musical composition and other musical activities.
He concentrated more and more on tuning theory, especially in relation to just
intonation and 31-tone tuning. He began a larger enterprise of instrument
building, namely an organ with the full scale of 31 tones per octave. He
secured enough financial aid for its construction, and the organ - of his own
design - was installed in Teyler's Museum in 1950. It is now usually called the
"Fokker organ". It has a main console with two 31-tone manuals and a pedal
keyboard, and an additional console with 12-tone keyboards on which portions of
the 31-tone scale can be played. The first organist was Paul Christiaan van
Westering. The first concert on the new organ was given on 10 September 1951,
with compositions by Jan Pieterszoon Sweelinck, Paul Christiaan van Westering
and Jan van Dijk. Concerts involving the organ
took place frequently during the period 1951-1955, featuring both newly-written
31-tone music on the main keyboard and early music on the meantone option of
the additional, 12-tone keyboard. Since then concerts were given on each first
Sunday of the month, except in January.
For sound examples of the Fokker organ, go to the CD-page.
Schematic representation of the keyboard design of the Fokker organ.
A.D. Fokker: About the construction of the 31-tone organ
Photos after the renovation
Renovation Fokker organ
In 2008/2009 the Fokker organ was completely renovated and was placed in the Small Hall of the Muziekgebouw aan 't IJ. Read all about the renovation of the Fokker-organ here.