Tonewood by Hugo Morales Murguía

Tonewood Hugo Morales
A tactile transducer as used in the Tonewood pieces: 2 cm cork on top, and some felt to not harm the instrument. © Hugo Morales Murguía

Tonewood I (2011) and Tonewood II (2015) by Hugo Morales Murguía are using small tactile transducers with corks attached to their cone. Five musicians play their instruments with these transducers. The transducers are not sounding at all, as long as they are not pressed to any surface. During Tonewood they are pressed against the wood of the soundboards of violins, guitars, violas, violoncellos, double basses or pianos. In this way, their soundboards become a kind of membrane for the transducers. As Hugo describes in the score:

The term “tonewood” generally refers to any wood which may be used in the construction of a musical instrument, specifically string instruments. An intrinsic characteristic of these instruments is the use of a resonant chamber, or sound-box, which not only projects the sound of the instrument but provides personality and quality to the overall sound of the instrument depending on its size, architecture and different kinds of wood used in its elaboration. This piece explores the internal resonances of each instrument and the way these correlate with the external performance space. For this, each instrument is continuously “scanned” through a series of impulses, exciting several resonant modes and projecting different overtones resulting in complex harmonic relationships.

Score Tonewood Hugo Morales
At the beginning of the piece the instruments slowly fade in. © Hugo Morales Murguía

Very minimal material is diffused through the transducers: just a pulse repeated each 80 ms and a sine wave of 659 Hz (pitch e). These are generated by the music software Max. To scan their instruments the musicians follow a score in which three different aspects are notated. First of all, the volume of the sound diffused by the transducer (thus being the volume of the 80 ms clicks or the 659 Hz). They control this with a volume pedal. The second aspect is the amount of pressure the player uses to push the transducer against the instrument: low pressure, normal pressure and overpressure are the indications mentioned in the score. The last aspect is the placement of the transducer on the instrument, which is indicated by 4 (Tonewood I) or 9 (Tonewood II) numbers.

tonewood Hugo Morales
The nine different spots used for pressing the transducer against the instrument in Tonewood II. © Hugo Morales Murguía

This piece is not played on the strings of the instruments and neither fingers nor bow movements are producing the sounds. For this reason, the five musicians playing this piece turn their instruments around. This allows them to easier access the soundboard of their string instruments.

Ensemble Vortex rehearsal Tonewood Hugo Morales
Double bass player Jocelyn Rudasigwa during a rehearsal of Ensemble Vortex: she has turned her double bass around and is scanning her instrument with a transducer.
Tonewood Hugo Morales
Tonewood II starts with quick changes between normal pressure and overpressure,  a crescendo of the pulses controlled with the volume pedal and the transducer placed on the middle of the instrument. © Hugo Morales Murguía

This is a video documentation of Tonewood I performed by ensemble Modelo62 . Just having the same pulse repeated till nearly the very end of the piece opens your ears for a miniature world of sonic changes, all caused by the resonating bodies of the instruments themselves.

The system of Hugo reminds me a little bit of Ute Wassermann’s Windy Gong, for which she uses a loudspeaker with a cork placed on top. And indeed: Hugo confirmed me that he had been influenced by Wassermann’s loudspeaker after reading about it in Nicolas Collin‘s great book Handmade Electronic Music. This is—by the way—an indispensable book not only for those interested in hardware hacking in general, but also for several hands-on microphone and loudspeaker technologies. Chapters such as How to make a contact mike, The celebrated jumping speaker of bowers county, or Turn your tiny wall into a speaker are great sources of inspiration.

Tone wood II is going to be performed on the 30th of March in Geneva, so if you are close by, you can attend the concert by Ensemble Vortex during the Archipel Festival.

Klangflug by Lara Stanic

Lara Stanic Klangflug flying loudspeakers
Lara Stanic performs Klangflug. © Lara Stanic

In her performance Klangflug (2006 – 2013, several versions) Lara Stanic looks for ways to transmit the airiness and volatility of sound itself to the heavy loudspeakers, needed to produce sounds. By simulating sounds of an airplane taking off on her flute, she sets the loudspeakers free and they start to travel through the air. The result are flying loudspeakers.

This is done by attaching four big helium balloons to four loudspeakers. Lara puts sugar on top of the loudspeakers to keep them on the floor. She starts to play glissandi on her flute now, simulating airplane departure noises. These glissandi are picked up by a microphone and sent to the music software Max, using pitch shifter to  transpose and enlarge the glissandi.  These sounds are diffused through the four loudspeakers with sugar on top. As can be seen in this short demonstration movie, at certain frequencies, especially low ones, the movements of the loudspeaker membrane cause the sugar to fall off. The helium balloon will now ascend into the air, taking the loudspeaker with it:

During the performance the pitch shifters prolong Lara’s glissandi on the flute more and more, enlarging the possible glissando range of the flute. Lara explained to me, that the balance of the weight of the sugar piles, big enough helium balloons and right pitches on the flute is very delicate. The amount of time it takes to free each loudspeaker is variable for each performance, and the height of their flight is depending on how much sugar is left on the loudspeaker. When I attended this performance, exactly this unpredictability was so fascinating: the big balloons and the rising pitches built up the tension, whereas the final taking off of a loudspeaker always came as a surprise.

The movement of the loudspeakers is only visually perceivable in the movie documenting the performance. Evidently, when hearing this performance live, an important aspect is also the upwards movement of the sound. (And if you are curious why sugar is used: I asked Lara and she told me it was just a result of trial and error with different kinds of sand, sugar and other material.)

Lara has created many works for microphones and loudspeakers, another example is Open Air Bach. Other artists have focused not so much on the taking off, but especially on the flight itself of loudspeakers. Works by Lucio Capece, Fabrice Moinet and Genoel Lilienstern are interesting examples (and I will write about these works in the future ).

A sympathetic piano by Gökhan Deneç

The electromagnets attached 2 mm. above the piano strings to create a sympathetic piano. © Gökhan Deneç

In Chapter Three of my book I discussed several early attempts of creating electric piano’s during the end of the nineteenth century. Often these efforts made use of electromagnets and feedback to keep the piano strings in vibration. The Neo Bechstein was one of the first commercially available results, but did not use any feedback anymore. During recent years new compositions and systems using electromagnets or tactile transducers and feedback for sound shaping and diffusing have been developed, for example by Per Blond, Andrew McPherson and Rama Gottfried (I’ll post about them in the future). Also Wave Train (1966) by David Behrman is related to these kinds of electric piano’s.

The hand-wounded electromagnets, with the permanent magnets inside the plastic reel.
The hand-wounded electromagnets, with the permanent magnets inside the plastic reel. © Gökhan Deneç

Gökhan Deneç has developed a sympathetic resonance system for a piano using electromagnets and feedback through its strings. He developed his own hand-wound transducers for this, using a simple but effective combination of wire, magnets and plastic reels. These electromagnets are placed in a grand piano and hung approximately 2 mm above the strings. The piano strings are attracted and repelled by the magnetic fields caused by these electromagnets. By sending the same signal through all electromagnets each piano string will start to vibrate, depending on how much its partial tones relate to the spectrum of the signal sent through the electromagnets.  A contact microphone (a model similar to an AKG C-411) is attached to the soundboard of the piano. In between this microphone and array of electromagnets a Pure Data patch is controlling and shaping the signal to the electromagnets. As Gökhan explains:

”My first intention was to create feedback to excite the piano strings and then by manipulating it I would create textures. Then I decided to define some possible regions for feedback to occur by sending an initial sound and also accompany the feedback by these textures. Also, I have a filtering algorithm that keeps the feedback under control. […] The sound creation is realised in PureData; there is a generative algorithm that I designed to create a very specific type of sound world. […] What you hear in the video is the generated tones that are created to vibrate the piano strings and because of its nature, they are unique in their own time. I can not repeat the same sounds, there are tons of randomization going on to construct this generativeness.”

This sound processing is controlled by the amplitude of the feedback signal coming from the contact microphone. Gökhan created an algorithm which is generating clusters of ten pitches, relating to the number of our fingers. A detailed explanation about how this all functions can be found in his PhD research. His PhD is entitled Creating sound mass using live sound processing and feedback with sympathetic vibrating strings and was defended in 2015 at Istanbul Technical University.

Gökhan Deneç is continually developing this project, so if you are a composer or sound designer interested in this system and would like to experiment or even compose a piece for this, please feel invited to contact him!

The Pure Data patch with a ten pitch cluster.
The Pure Data patch with a ten pitch cluster. © Gökhan Deneç

An active loudspeaker by Hermann Scherchen

loudspeaker ball nullstrahler hermann scherchen
The rotating loudspeaker ball with 32 loudspeakers developed by Hermann Scherchen (source http://www.studiodabbeni.ch/exhibitions/20/hermann-scherchen:-alles-hörbar-machen-i).

Due to his intensive occupation with recording and reproduction of music the conductor Hermann Scherchen (1891-1966)  became aware of the enormous increment of people listening to music through loudspeakers. He was concerned about the difference between the complex sound diffusion during a concert by the whole orchestra and the very poor representation of the music through one loudspeaker (at that time sound diffusion was often still mono). Scherchen aimed for a recording to sound as if performed in the (acoustic) space, in which it was reproduced and in which the listener of the recording was present. To achieve this, loudspeakers should diffuse sound in such a way, that they “trigger” the acoustics of the space. The recording is not anymore a reproduction of a musical event, which had happened in another space and another time, but the recording now becomes a musical event in itself, sounding as if the instruments are playing in your living room.

To achieve this effect, Scherchen invented a rotating loudspeaker ball, or, as it was called by him, „Der aktive Lautsprecher“ (the active loudspeaker) or “Nullstrahler” (which could be translated as zero radiator, since it was diffusing sound in all directions). Scherchen looked for an alternative for stereophonic reproduction, which in his opinion could not reproduce the sound perception in a space. The rotating loudspeaker ball was developed to distribute the sound in such a way, that each member of the public would sit inside the „sweet spot“ or actually no sweet spot was existing anymore. This loudspeaker was developed in 1959 and consisted of 32 speakers (215 mm diameter) placed on a 70 cm ball. The weight of the whole construction was 150 kilogram. This ball was placed on a stand and able to rotate in all directions. The music played on this loudspeaker ball was not experimental at all, but for example J.S.Bach’s St. Matthew Passion. (I would love to experiment with these loudspeakers though!)

I only have a very bad picture but apparently listening to this loudspeaker was also done outside (in Gravesano, Switzerland, where Scherchen lived). In the second picture you can see the loudspeaker ball in the middle and the audience sitting around:

Nullstrahler loudspeaker ball hermann scherchen
The “Nullstrahler” in action during a meeting in Gravesano.

A beautiful documentation of an exhibition on Herrmann Scherchen’s electroacoustic research has been made by Luca Frei. Bruno Spoerri wrote a detailed history on Scherahen’s studio in Gravesend (see the article Hermann Scherchen und das Experimentalstudio Gravesano (1954–1966) in the book Musik aus dem nichts).

In this video the loudspeaker ball can be seen in rotation (the music heard in the video seems not to be diffused by the loudspeaker ball though):

 

The loudspeaker has been renovated at the Studio für Elektroakustische Musik der Akademie der Künste, and will appear in concert during the Kontakte Festival (28.09. – 1.10.2017).

More information on this loudspeaker ball can be found in the archive of the Akademie der Künste Berlin and in several volumes of the Gravesaner Blätter:

“Fünf Jahre Gravesano“ (1954 – 1959) in: Gravesaner Blätter No. XIV Volume IV 1959 p. 2.

Technical aspects at the Fifth Anniversary of Gravesano, F. A. Loescher, Gravesaner Blätter No. XV/XVI Vol. IV 1960, p. 6 – 7

Annea Lockwood’s loudspeaker ball  also diffuses monophonic sound through many loudspeakers. And spherical and hemispherical loudspeakers have also been used by laptop orchestras such as the Plork.