It is now widely known among a growing audience that Professor Adriaan Fokker had the 31-tone organ built in 1950. What few people realise, however, is that in 1943, as curator of the Physical Cabinet at the Teylers Museum, he also took the initiative to have another organ constructed, the so-called Euler organ. And yet, each year thousands of visitors walk past this remarkable little organ in a hall full of historical scientific instruments in this Haarlem museum.
How this Euler organ sounded and what music was composed for it has largely been forgotten, as the little organ has long been unplayable and the sheet music of its associated repertoire—which developed over only a seven-year period—is stored in the archive of the Huygens-Fokker Foundation in Amsterdam. This provides a wonderful opportunity, seventy-five years after the completion of the Euler organ, to investigate how the instrument once sounded!
First, research was conducted to determine the type of metal open organ pipe used in the Euler organ. Highly realistic samples of exactly the same organ stops will be used during this concert, played from behind the console of the Fokker organ, to finally bring this mysterious little organ to life. This virtual organ is carefully tuned so that the so-called “Euler-Fokker genera of the third degree” can be heard. In this way, the first microtonal compositions by Fokker—short pieces to demonstrate the ten genera on the little organ—will also be performed.
Other composers have also written for the Euler organ, including Jan van Dijk, Henri Carf (Henk van Kempen), and Martin J. Lürsen, who, among other achievements, won the “Teylers Musical Competition” in 1945 with their works. Of particular note is that, specially for this concert—and for the day when the Euler organ in Haarlem may once again be playable—a new work for the Euler organ has been composed by the Dutch composer Gijsbrecht Roijé.
All of these compositions will be interspersed by the resident Fokker organist Ere Lievonen with works from the acoustic 31-tone organ repertoire, so that the difference in tuning can be highlighted as clearly as possible. To complete the experience, photographs of the original Euler organ will be projected onto a screen during the concert. In this way, this mysterious little organ comes briefly back to life this Sunday morning.