A Spatial Composition

for two pioneering instruments

Helder Tenor Recorder & Icosahedral Loudspeaker




Inspired by German recorder models from the 1930s[1] and especially by the intense research on these instruments by Nik Tarasov[2], Dutch recorder maker Maarten Helder developed a new Tenor recorder in the early 1990s.

This instrument got into the focus of keen recorder players right away, was even praised as “first true revolution since Hotteterre”[3] by Dutch recorder virtuoso Walter van Hauwe and is now known as the HELDER TENOR.

Like a few other musicians and makers, Maarten felt too restricted with the recorders built in these days, especially when it came to dynamics, expression and range. Copies of mainly 18th century recorders had to be (and still have to be) tuned in 440 Hz and higher in order to be combinable with contemporary instruments. This implied compromises for the whole instrument and its disadvantages, like e.g. too soft low register and too unstable third octave, even increased. Maarten asked himself if there could be a possibility to make an instrument with a well-balanced, strong sound through three entire octaves, still being able to use baroque fingerings through the first two octaves.

During his research of the instruments from the 1930s, Maarten realized that next to their strong sound they include an interesting feature, which is anyway the principle of every modern woodwind making: the two bottom notes could be overblown into pure tuned harmonics. After a few years of physical calculations and empirically experiments, Maarten developed the first prototype of the Helder Tenor, which he presented for example at the “Hochschule für Musik und Tanz Köln” in December 1993[4].

In 1995 he sold his first tenor recorder and first pieces were especially written for it and premiered by recorder players, like Johannes Fischer, Jospeh Grau and Walter van Hauwe[5]. The production of the Helder Tenor was quite expensive, so it was clear that Maarten had to find a collaborator soon. In spring 1996 recorder workshop Mollenhauer took over the production of the Helder Tenor and was able to develop the instrument further, especially regarding its voicing and key mechanism. Maarten was supervising the production until 1999 and helped to develop an alto recorder version.

Articles have been written about the Helder instruments and professional recorder players have been playing on them ever since. However, one is waiting for the big break through. Now, that I get to know the instrument much better through my studies with Johannes Fischer and also through my own research, I wonder why – and on the other hand also understand why. It is one thing to play on this instrument, but a totally different thing to handle its full potential. So, what exactly is different and what exactly do I need to change?
Technically speaking a lot of things have changed in comparison to a 18th century recorder: bore, length, weight, key work, embouchure and not to forget the additional piano key – pretty much anything you can think of. A challenge, indeed, but also a chance towards an extended performance practice for advanced players.


Strong sounding first octave like we already know from renaissance recorders. The key system enables additional forte fingerings (for: d#1, f1, f#1, g1, a1, a#1, b), which are very rich in overtones.

While overblowing the two bottom notes, the first five harmonics are tuned pure. These harmonics can be used as alternative fingerings and therefore be played quite softly.

Second and third register are extended and chromatically well balanced except the top notes, which have to be slurred: b1-b2 (2nd register) and f#2- c#3 (3rd register)
In the first two octaves standard baroque fingerings work as well as piano fingerings and any other alternations you can think of.

The third octave is played completely without closing the bottom hole – but of course you can still use fingerings with closed bottom hole (some of them work even better and are better in tune then. This is also the reason why Johannes Fischer did ask for a stopped foot joint with an extra bottom key at the side). Since many of the fingerings are based on harmonics and work with “shadowed” fingerings, many of these notes can be played softly.

Through the PIANO KEY (used with left index finger) one can play softly with standard fingerings (without changing the pitch, but still keeping the sound quality of the standard fingering) as well as make a smooth crescendo and decrescendo, depending on the note and register you play. I am already using an extended version of this key, which is able to gradually open and close.

Through the SOUND UNIT one can

adjust the size of the windway in order to react on temperature and humidity, but also to change the general sound quality (from noisy to very airy)

adjust the height of the windway exit (it appears to be not as useful as its inventors were hoping for)

decide the material of the windway roof (expandable)

close and open the entrance of the windway while playing (one needs to learn a different embouchure)

Quite some nice features, but as I mentioned before, also quite challenging. Most of the features demand very virtuoso and extended finger techniques as well as new positions for the tongue articulation and different embouchure using the lip control.

[1] Thalheimer, Peter: Die Blockflöte in Deutschland 1920–1945. Instrumentenbau und Aspekte zur Spielpraxis; Tutzing 2010 (Tübinger Beiträge zur Musikwissenschaft, Band 32).
[2] Tarasov, Nikolaj: Harmonische Blockflöten. Die Geschichte einer neuen Blockflöten-Generation; in: Windkanal 2/2004, S. 14–21.
[3] van Hauwe, Walter: recorder versus blockflute; in: Windkanal 2/1997, S. 6-7.
[4] Schubert, Nadja: Helder-Blockflöten. Harmonische Blockflöten als neue Generation in der Blockflötenfamilie; in: Windkanal 2/2002, S. 22–24.
[5] Helder, Maarten: Die rein überblasende Blockflöte; in: 4. Internationales Blockflöten-Symposium Kassel 6.–9. Juni 1996, ERTA-Kongress, Vorträge und Dokumentation; Karlsruhe 1996, S. 39–44.