The ‘Hellertion’ and The ‘Heliophon’. Bruno Helberger & Peter Lertes, Germany, 1929-1936

The Hellertion, christened after the combination of the inventor’s names, was a monophonic vacuum tube instrument developed collaboratively by Peter Lertes, an electrical engineer in Leipzig and Bruno Helberger from Frankfurt, a well-known pianist of his time. Helberger was inspired to build the instrument after witnessing Termen’s Theremin – possibly at the Neue Frankfurt exhibition in 1927. ¹ Donhauser, Peter, Elektrische Klangmaschinen. Die Pionierzeit in Deutschland und Österreich, Böhlau, Wien, 2007, 46. Several variants of the instrument were constructed and promoted through a licensing arrangement with the Schneider-Opel AG radio company in Frankfurt, who positioned the new instrument as ‘a portable, multi-voice instrument that can be connected to any radio with record amplification’. Although the deal eventually fell through with the collapse of Schneider-Opel in 1932, the Hellertion can be seen as the world’s first commercially produced electronic musical instrument.

The Hellertion was the first electronic instruments to use a fingerboard/continuous controller instead of a keyboard manual a feature that was to influence the design of later electronic instruments particularly Trautwein’s Trautonium (essentially a licensed derivation of the Hellertion) and the soviet instrument called the Sonar. The fingerboard was a flat metal resistance strip covered in leather which when pressed completed a circuit. Depending on where the strip is pressed, a different resistance in the circuit is created altering the voltage sent to the oscillator and thereby producing different pitches. The force of the pressure controlled the volume of the output signal. The fingerboard was marked to help the performer find the correct pitch on the strip and had a range of approximately five octaves.

The original instrument had just one fingerboard strip which was gradually increased to four and then on the later models, six aligned in parallel horizontally at the height of a piano keyboard. The four and six strip models allowed four and six voice polyphony when the strip could be played simultaneously with fingers and thumbs. The Hellertion was occasionally used in concerts as a piano addition, the melody being played with one hand on the Hellertion and the accompaniment being played with the other hand on the piano. A version of the Hellertion was produced in 1931 microtonally tuned to 10 divisions of an octave.

At the outbreak of war where around 1940 began constructing an enhanced version of the Hellertion he called the Heliophon. Helberger continued the development of the Helertion creating an enhanced keyboard version of the Hellertion he called the Heliophon. The first version of the Heliophon was completed in Berlin, 1936, but destroyed during WW2. Helberger moved to Hörzendorf in Austria where he constructed a second model Heliophon in 1947 and continued the development of the instrument until his death in Vienna in 1951 (subsequent development was taken over by Wolfgang Wehrmann).

The sound of Heliophon was produced, as with the Hellertion, by heterodyning vacuum tube oscillators but with the Heliophon the sound was controlled by two 58 note pressure sensitive keyboard manuals instead of a series of fingerboard strips. Each keyboard had the ability to be split into three different pitches and timbres simultaneously, the output volume being controlled by foot pedals with a knee lever to add vibrato. Each keyboard had a Hellertion style fingerboard to add glissando and timbre variations which gave the instrument a remarkable versatility, apparently capable of producing realistic imitations of orchestral instruments as well as imitate human vocal sounds. The Heliophon was used by Helberger throughout the 1940s and ’50s for theatrical, film and musical productions.

The Heliophon on the soundtrack to Leopold Rudolf’s Der Rabe 1951