On 7th and 8 th July 2023 at the Parco Dora in Tourin, The electronic music is the very protagonist. This edition of Kappa Future Festival hosted 40 artists for a total of 24 hours of music divided within two days, each starting from 12 am till midnight.        

 FutureFestival born in the 2009 to celebrate the 100th anniversary of the Futurism, has always hosted the most important artists of the musical world, becoming in 2015 the first format in Italy introducing the cashless technology, a new system that allows you to buy inside the festival area only by means of a prepaid card that substitutes cash.                                 Thanks to the success of the previous editions, the festival has been mentioned on the Times newspaper, as the main event of the year conquering the attendance record from abroad, hosting up to 62 different nations.                         More than 50.000 people has come from all around the world to enjoy one of a kind experience. …What can you breathe inside the Parco Dora? The feeling of being part of something huge.

This was the alien Line Up:

Day 1 – Saturday 7 Luglio

JAGER STAGE: APPARAT DJ Set, ERIC PRYDZ, JOSEPH CAPRIATI, KÖLSCH, LOLLINO, SOLOMUN, THE MARTINEZ BROTHERS, TIMO MAAS                                                            

BURN STAGE: ANDREA OLIVA, DJ TENNIS, EATS EVERYTHING, GIORGIA ANGIULI Live, PATRICK TOPPING, RICHY AHMED                                                                                            

FUTUR STAGE: ADAM BEYER, AMELIE LENS, MARCO FARAONE, SAM PAGANINI      

DORA STAGE: BODY & SOUL, FRANÇOIS K, JOAQUIN “JOE” CLAUSSELL, DANNY KRIVIT, Live Performance JOSH MILAN (from BLAZE)

Day 2 – Sunday 8 Luglio

JAGER STAGE: FATBOY SLIM, JAMIE JONES, KiNK Live, LUCIANO, MARCO CAROLA, SETH TROXLER, STACEY PULLEN                                                                                            

BURN STAGE: ADRIATIQUE ,DJ RALF, HOT SINCE 82, JACKMASTER, PACO OSUNA  

FUTUR STAGE: DERRICK MAY, ILARIO ALICANTE, PAN-POT, ROBERT HOOD, RØDHÅD 

DORA STAGE: MR FINGERS Live aka LARRY HEARD, MOTOR CITY DRUM ENSEMBLE, PEGGY GOU

It mustn’t be that easy to figure out how to organize a timetable able to valorize both the stages and the artists, but FutureFestival did it. Instead of focusing all the “bigs” at the end of each slot, they achieved a heterogeneous distribution among the entire day. Given the high number of Dj’s, in this edition has been set up another stage: Jäger (its name already suggests what kind of music this area reserved…).

Within 12 hours of music is quite difficult to find lazy spots, if a stage presents someone that we for example don’t like, we have other three possibilities to find someone else that makes us fell half that good. There is no discrimination, some headliner are playing at 15 on the Main Stage while others at 22.                                                                                                  This strategy provides entry from the very beginning of the festival, collecting the most fancy and variegated audience in all groups of ages , from 18 up to 50 years old.

Due to the huge turnout of this edition, the entrance has been divided into gate A and B, two endless walkways equipped with turnstiles and security, each of 20 meters. The inspection made by the police was maniacal, besides the search and the metal detectors, each person had to be checked by the search dogs that where looking for drugs and explosives. I red on the newspaper that only during the first day, more than one kilos Hashish and 500 pills where seized.                              After more or less one hour waiting in line, you could finally access into the festival’s area.    

The location plays an important role inside this adventure. Parco Dora offers 450.000 square meters of space, with a river that in the past was not accessible due the factories. Nevertheless the decontamination, this park reminds the industrial life typical of that part of the city, by keeping most of the pre-existing building, like steel hangars and chimneys. Stationed between grass and iron, the stages where build all around the area. The main one (Jäger) was characterized by this huge open-air rectangular hall, with an iron roof on a cement floor, a minimal structure decorated only by means of speakers all around the ring.                                                                                                                                  The other stages where looming on grass and mulch, giving the possibility to chilling in the sun, listening to a “softer” sound, drinking a cocktail or a beer sold by the several stands spread all around the area.                                                        Peculiarity of this allocation where the ways used to link the different location.                                                                            The organization created a sort of path through the ruins and the rubbles, reviving what might have been the industrial life at that time.

Despite the massive success and the maniacal organization, I think that the “Sound” factor was a bit overlooked. Due to the different normative about the breaches of the peace, FutureFestival, different from the others editions, adopted a peaceful political by reducing drastically the volume. It’s incredibly frustrating to see 20 meters line array towers and 70 subwoofer playing as an open-air theater. Ignoring the sound feedback between the stages, perhaps because was required a better and more precise acoustic intervention for that situation, it was unavoidable to listen to the surrounding area instead of the music.

Techno music is a very standard and metric genre, the entire construction is based on the subdivision of the piece into: Intro, Breakdown and Drop, the “pumping” part. Elements to appreciate this music are the volume and the pressure that, together, play an important role on the perception… even a cheesy composition can sounds amazing with the correct amplification. From this point of view the Kappa FutureFestival was a flop, the only solution, to get the sound from one source, was to get closer to the stage, among the most fiercest ravers, surviving the bumps and the jabs. Really to appreciate have been the visuals, that through projections and screens have colored this unique adventure.

Kappa FutureFestival remains, without a doubt, a great experience to meet fantastic people and to have an electronic contact with the world. Waiting for the next appointment…

As a reference for this project, I present two different examples that I researched for the realization of the “One Wire Hackbrett”. Approaching these projects, I got an idea of how to realize the instrument and the different ways of playing it. Even though both examples could result similarly from the technical point of view, each of them presents innovative aspects that I can implement into my project:

• “Autoklavierspieler”: realized by Winfried Ritsch, is a robot piano player, also called “Vorsetzer”, designed to play every common (grand) piano with individual dynamics for each key as fast as possible. A massive frame with 88 electromechanical fingers, which are moved by solenoids, is mounted on a keyboard. Controlled by microcontrollers, which are driven over a dedicated computer, the “Autoklavierspieler” can be controlled over Network, MIDI files and real-time generated algorithmic music.[1]

An example of its application can be seen at the following link: https://www.youtube.com/watch?v=Wpt3lmSFW3k

• “ballet mécanique”: is the most famous composition of the American composer George Antheil. Originally composed to be a soundtrack of a film, the composition is composed for 16-player pianos, four kick drums, three xylophones, a tam-tam, seven electric bells, a siren, and three propellors. [2] Since the technological possibilities of the time did not allow for the creation of a machine capable of playing and synchronizing instruments with each other, this performance became a challenge for several contemporary performers. I had the pleasure and opportunity to work with Professor Ritsch during the preparation of his version of the piece.

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[1] Autoklavierspieler Overview (2022) Atelier Algorythmics. Available at: https://algo.mur.at/projects/autoklavierspieler/overview (Accessed: January 23, 2023).

[2] https://www.antheil.org/balletmec.html

Since I have already assembled the electrical parts necessary to be able to play the instrument, next semester will focus mainly on the realization of the physical prototype through the following steps:

1. Implement PlatformIO[1] to connect the Arduino´s codes together and have a better and more fluent programming environment;

• create a GUI that communicates with the instrument via Wi-Fi. Through OSC messages, I will map the following parameters:
  • the time interval between the beats of the solenoid;
  • velocity;
  • the degrees of rotation of the lever to vary the pitch;
  • the degrees of rotation of the tuning screws;

• build two wooden sticks to support two hammers for each string. At this point would be interesting to implement additional DC motors, like for a 3D printer, to control the movement of the sticks along the strings to get timbral variations;

• change the tuning system of the “Hackbrett”, similar to a guitar´s one, to decrease the required torsion force for the DC motor to rotate them;

• create different supports that fits the servos in order to change the tuning of the strings;

• regarding the performative aspect of this instrument, I will implement one IR sensor to control the lever. I will map the movement of the hand to the steps of the motor to change the pitch through movement,

• implement a small DC motor to control a sort of mute rail of the piano, damping the strings.

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[1] PlatformIO (no date) Platformio is a professional collaborative platform for embedded development, PlatformIO. Available at: https://platformio.org/ (Accessed: January 26, 2023).

Here the circuit of the “One Wire Hackbrett”:

After applying the 24V power supply to the circuit, the signal splits into two directions. The first one goes directly to the Solenoids that are driven with PWM signals through the microcontroller:

• PWM stands for Pulse Width Modulation. It is a technique used to control the amount of power delivered to a load by controlling the duration of a series of pulses. The duty cycle of a PWM signal is the proportion of time that the signal is in the “on” state (high) compared to the total period of the signal. It is typically expressed as a percentage. For example, if a PWM signal has a duty cycle of 50%, it means that the signal is in the “on” state 50% of the time and in the “off” state 50% of the time. The relation between the duty cycle and the power delivered to the load is that a higher duty cycle corresponds to more power delivered to the load. To avoid burning the magnet,

The second goes across the DC/DC Stepdown converter that transforms the power into 5V since the ESP32 microcontroller produces only 3.3V (not enough to drive efficiently the motors).

Besides this project, I had already some experiences this semester to explore the possibilities in the field of music machines. For the final presentation in “ESC medien kunst labor” I presented a plastic “Hackbrett” played by one DC Motor. The generated sound was then recorded and processed in real-time via PureData.

The interaction with the instrument occurred using a 3D-printed cylinder mounted on the motor. The different slices on the sides were positioned at equal distances to insert guitar picks. The goal was to emulate an analog score capable to play different patterns according to the distances between the picks.

Even though this process seemed to be satisfying, due to the distance to the strings and the movement of the motor, it was difficult to manage a continuous pattern or intensity. For this reason, after discussing the idea with professor Ritsch, we obtain for the solenoids to play the instrument.

Next, I designed a prototype with only one string and a hammer with additionally a lever to be able to change the pitch of the string and obtain further nuances in the timbre.   The idea is to build a simplified version of the final machine to analyze the possibilities, limitations, and different technical challenges of this instrument. Although the construction is very rudimentary, through this process, I would learn useful information to better set the technical components and then decide how to play it from the artistic point of view.

The system works mechanically through two core elements: the hammer that reproduces the percussive sounds (solenoid) and the lever (servo motor) that contributes to shifting the pitch. With the first one I reproduce different rhythmical patterns that can be modified in real-time by means of pre-programmed sequences and with the lever, like for an electric guitar, I produce timbral variations in the frequency domain.

The image below represents the first sketch of the prototype:

Regarding the electronic part of the development process, I took inspiration from a project made by Professor Ritsch during my second semester at IEM, the “Coeus”:

“previous “autodrummer” and later percussion robot aka “Doppelschlagwerke”, now robot musician is targeted building robotic instrument player with microcontrollers in the IoT generation, which are designed to play all kind of drums, gongs, pipes, strings … or other similar new created instruments or sounding objects very accurate and  dynamically as quickly as possible or slow with optional dampers – making up a automata as instrument player, a robotic musician controllable over a network via OSC (Open Sound Control Syntax).”[1]

Analyzing his concept, I reorganized the electronic parts I needed to design a robot that would meet my technical requirements. Here the list of electronic components that I used:

• One Solenoid push-pull;
• DC Motor[2];
• DC/DC Stepdown converter[3];
• ESP32-DevKit-Lipo with battery over WIFI;
• 24V external power supply

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[1] https://git.iem.at/ritsch/coeus/-/tree/master/

[2] Servomotor – CDN-Reichelt.de (no date). Available at: https://cdn-reichelt.de/documents/datenblatt/A300/COM-MOTOR02-DATENBLATT.pdf (Accessed: January 26, 2023).

[3] DC-DC Stepdown Modul LM2596S (no date) 3DJake Österreich. Available at: https://www.3djake.at/bigtreetech/dc-dc-stepdown-modul?gclid=CjwKCAiA5sieBhBnEiwAR9oh2v_YBqQJkIaTMVZ3Pr1sqGGeMtlf2k7Fa4m72bm-v9hGE5iRAfGhzxoCTWoQAvD_BwE (Accessed: January 26, 2023).

The “Hackbrett”, also known as a hammered dulcimer, is a stringed musical instrument that is played by striking the strings with small hammers. The strings are stretched over a trapezoidal-shaped soundboard and are divided into two sections: the treble, and the bass. The treble section typically has more strings and is played with the right hand, while the bass section has fewer strings and is played with the left hand.

It is a diatonic instrument, meaning that the notes it produces are based on a specific diatonic scale and not chromatic like piano for instance.

The hammers or beaters have padded heads, which allow the player to produce a variety of different tones and dynamics depending on the amount of force used to strike the strings.

The “Hackbrett” is a versatile instrument that can be used to play a wide range of musical styles, including folk, classical, and popular music. It has a unique and distinctive sound that is often used to add a touch of character and interest to a musical arrangement.

The way it works is by using the hammers to strike the strings, the hammers will make the strings vibrate and produce sound waves. These sound waves will then travel through the soundboard and out of the instrument, which is how the sound is projected. The hammers can be used to strike the strings at different points along their length, which produces different pitches.

The “Hackbrett” has a long and rich history in Austria, where it has been played for centuries. The earliest known reference to the instrument in Austria dates back to the 15th century. The instrument was brought to Austria by German and Italian traders, and it quickly became popular among the peasant population.

In the 16th and 17th centuries, was primarily used as an accompaniment instrument for folk music and dances. It was also commonly used in religious music and in the courts of noblemen and aristocrats. The instrument’s unique sound and versatility made it a popular choice for both solo and ensemble performances.

During the 18th and 19th centuries, the “Hackbrett” experienced a decline in popularity, as it was replaced by the piano in many musical settings. However, the instrument continued to be played in rural areas and among folk musicians, who kept the tradition alive.

The “Hackbrett” is essentially a resonance box with strings strung above it that are played with wooden sticks, “Ruten” or “Schlägerli” in German. One note can be played onE up to five strings. Choruses are the name given to such chords. 

A middle bridge that divides the strings in a specific ratio is frequently found on these choirs. Pure fifth results, for instance, from dividing a string in the ratio 2:3. This could mean, for instance, that a C is located on the bridge’s right side and a G is located on its left, or the opposite. For the best results, you should hit the strings three to four centimeters from the bridges.

After concluding my studies at the Institute for electronic music (IEM), where I wrote my bachelor thesis about a possible application of a glove as a musical interface, I decided to continue my research in the field of music machines and their capabilities.

Since the Sound Design department of the “FH Joanneum” has been invited to participate to the event “Salzkammergut 2024” to produce a physical music machine employing the traditional instruments from that region, I focused my work on the analysis and research of the “Hackbrett” as a topic of this semester. I aim to discover the peculiarities of this percussive-melodic instrument to produce a prototype able to reproduce human behavior while playing it.

Using small electronic components such as DC motors and solenoids, this project attempts to reproduce the technique and aesthetics of this instrument. The final product will be a music machine equipped with different servo motors and two solenoids for each string.

Under the supervision of Professor Winfried Ritsch, I conducted some research regarding its tradition and its role in the Austrian culture, to propose a simplified system that should represent the core of the instrument that I’m going to build next semester: the “One Wire Hackbrett”.

During this semester, I was able to learn countless notions that led me to the realization of the first prototype of this instrument.

Despite the difficulties, I was able to narrow down the field of variables and question marks that stand between me and the realization of the final product. Through research and experimentation, I acquired the skills to be able to plan the following steps that separate me from the final goal: the realization of a fully automated Hackbrett.

About the physical construction of the instrument. The next step is to build a support capable of holding the hammers for each string of the instrument. As already demonstrated with the prototype, the aim is to obtain a modular structure that can be customized according to technical and artistic requirements.

From the software point of view, the next step is to create a GUI in Pure Data to control the instrument via OSC (Open Sound Control). As a starting point, I will use the library written by Professor Ritsch, LEMiot[1]:

“Making Computermusic Devices using ESP32x with various sensors and actors is the overall goal for the LEMiot project. Using IoT (Internet of Things) technology to interact in Music Performances and Theatre projects or as sound installations. This library is a firmware framework for controlling LEMiot boards using the library ‘OSC_networking’ as device and WiFi management, parameter storage and additionally a simple user interface with LEDs and buttons. Each board as an incarnation extends these functionalities by integrating additional sensors or actuators. The device can be controlled wirelessly using a special ‘OSC’ protocol. A Configuration Tool with Puredata as also a corresponding Puredata library”

This step will enable me to learn the different techniques for interacting with the instrument and the parameters to be mapped. Moreover, the skills to program my own Networking environment.

Another important step to be taken, is the realization of a functional algorithm for the pitch detection. As discussed in previous chapters, my initial approach involves utilizing zero crossing analysis on each individual set of strings. To accomplish this, I will divide my tasks into two sub-levels: software and hardware:

– regarding the software aspect, I will employ the “~zexy”[2] extension for Pure Data, developed by Professor Johannes Zmölnig. This extension provides valuable examples and resources for pitch detection using zero crossing techniques. By studying these principles, I will gain a solid foundation and understanding. Eventually, I aspire to write my own pitch detection algorithm directly on the microcontroller, allowing for a more streamlined and integrated solution.

– regarding the hardware part, I will use the Calliope-board[3] for the further developments.  This board offers several advantageous features, including six microphone inputs and an integrated Mosfet system designed for solenoids. These components encompass all the necessary elements to realize the final product effectively.

The final element that remains is the development and integration of a servo motor system for tuning the instrument. However, I have not yet discovered a suitable approach for this specific purpose. The Hackbrett’s strings are closely spaced, which presents a challenge in independently controlling them. Therefore, our initial step will involve designing a system similar to the one depicted in the provided image /Fig. 1).

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[1] Ritsch, Winfried UC / LEMiot library · gitlab, GitLab. Available at: https://git.iem.at/uC/LEMiotLib (Accessed: 16 June 2023).

[2] Pure Data Libraries / Zexy · GITLAB (no date) GitLab. Available at: https://git.iem.at/pd/zexy (Accessed: 16 June 2023).

[3] Ritsch, Winfried IEM development area, Sign in · GitLab. Available at: https://git.iem.at/ritsch/calliope (Accessed: 16 June 2023).

In the initial phase, I embarked on a series of experiments using PD (Pure Data) to analyze the input signal derived from my prototype. Here the aim was to understand how to get the parameters for the servos to tune the strings.

At first, I employed an FFT (Fast Fourier Transform) algorithm to determine the algorithm’s ability to track the pitch of the incoming signal and see how reactive and precise the analysis response while changing the tension of the strings.

To achieve that, once obtained the fundamental and the first three partials of the incoming signal, I divided the process into two steps:

• convert the difference of the estimated pitch and the incoming signal (changing the tension) into semitones:
  • “Semitones = 12 * log2(frequency / referenceFrequency)”;

• attribute the estimated difference in semitones as pitch parameter of a “pitchshifter”.

The limitation:

• FFT analysis of complex signals and the latency introduced while processing the data:
  •  the interference between the harmonics produced by different strings can create complex frequency interactions that are not easily captured by a simple conversion method. To improve the reliability of the analysis, it would be necessary to employ more sophisticated techniques that take into account the complex harmonic relationships occurring during simultaneous string play. This could involve employing advanced signal processing algorithms or considering the specific characteristics of each string, such as its tuning, tension, and resonance properties.

The second step consisted into the application of zero crossing analysis to find the pitch of the strings. Even though I was not able to implement this process during this semester, I came out with rather interesting solutions to implement it.

First a brief introduction to the subject… In the audio domain, zero crossing[1] is an important concept that is frequently used in pitch recognition and estimation. Pitch recognition refers to the process of identifying the fundamental frequency or musical pitch of a sound.

Zero crossing analysis is employed as a technique for pitch recognition due to its effectiveness and simplicity. The fundamental frequency of a sound corresponds to the rate at which the waveform crosses the zero level. By counting the number of zero crossings within a specific time frame, it is possible to estimate the pitch of the sound.

As we traverse through the audio samples, we examine each point. If the amplitude of the current sample (N) is equal to the silent threshold and the amplitude of the following sample (N + 1) is either higher or lower than the silent threshold, then the sample point at (N) is identified as a zero-crossing point. Once we determine the number of zero crossing points, we can utilize the sampling rate of the signal and the total number of samples to calculate the duration in seconds over which these zero crossing points were counted.

The formula for this calculation is:

Number of seconds = Total number of samples / Sampling rate

Considering that each oscillation of a signal encompasses two crossings of the silent threshold, we can determine the number of oscillations by dividing the total number of zero crossing points by two.

The formula is:

Number of oscillations = Total number of zero crossing points / 2

To ascertain the frequency of the input audio signal, we employ the values obtained from steps 2 and 3. The formula for calculating the frequency in Hertz is:

Frequency of input audio signal = Number of oscillations / Number of seconds

The methodology of zero crossing analysis offers various approaches and combinations that can yield accurate results. However, upon analyzing different projects, it becomes evident that limitations arise when the input signal comprises multiple simultaneous sounds rather than a single waveform.

To overcome the challenge of analyzing complex instruments like the Hackbrett, I have reached a possible realization for the upcoming developing time. When dealing with instruments that produce overlapping sound sources, such as multiple strings being played simultaneously, it becomes essential to implement a specialized approach to improve the accuracy and reliability of the analysis.

One effective solution involves recording each string separately and isolating their individual signals. Moreover, since we already know the frequencies associated with each string, we can leverage this information to our advantage by applying a “third-octave filter”[2] at the input stage to attenuate any potential interferences arising from other strings.

After researching about the topics, I encountered one project made at the IEM by Winfried Ritsch about acoustic of music instruments, the “IAAI[3]”:

“The basic idea is to use the acoustics of the instrument as an instrument, for example as part of a feedback loop. In the acoustics of an instrument, we consider the entire signal path, from the excitation of the strings to the radiation, so pickups in combination with loudspeakers and magnetic actuators for vibrating strings are also part of the acoustic system of the instrument”   

Even though the purpose of this research is focused on other aspects, it shows an implementation of technics that fit to my research about finding the best way to detect the pitch.

In the specific, the idea of using the “Varitone”[4] to build resonant filters.

The “Varitone” is an electronic circuit found in electric guitars that alters the sound by changing the frequency response. It uses capacitors and resistors connected to the guitar’s pickups to create a low-pass filter network. A rotary switch on the “Varitone” circuit selects different capacitor and resistor combinations, changing the cutoff frequency of the filter.

Rotating the “Varitone” switch modifies the circuit’s capacitors and resistors, which adjusts the cutoff frequency. This affects the amount of treble reduction, resulting in different tones. By passing the guitar signal through various capacitor and resistor combinations, the circuit modifies the frequency response, impacting the amount of high-frequency content reaching the amplifier and creating tonal variations. Since the principle of this system consists precisely in obtaining filters that can be set to different frequencies, I thought of combining this technique for a system of piezo microphones positioned on the instrument.

In the Fig. 8, a draft made by Professor Ritsch that represent the electronics of this system.

Once the strategy of how to apply the electronics to filter the input signal has been analyzed, I moved on asking myself how to record the signal coming from each string.  Here two approaches that I have identified as possible solutions to record the strings separately:

• handmade pickups made by ferrites;

• elastic pickups (Fig. 11) that I used in the past to build guitars and positioning them underneath each choir of the Hackbrett. The advantage of using this piezo is that I could cut them into small pieces and make different microphones from one stick. As we can see in the Fig. 10, I divide the strings into channels to be sent to the pitch detector. Once the analysis is done, I compare the outcoming frequency with the given one of the string to adjust then the servo motor.

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[1] Daoo, R. (2020) Algorithmic frequency/pitch detection series – part 1: Making a simple pitch tracker using zero…, Medium. Available at: https://medium.com/the-seekers-project/algorithmic-frequency-pitch-detection-series-part-1-making-a-simple-pitch-tracker-using-zero-9991327897a4 (Accessed: 09 June 2023).

[2] Third-octave filter banks. Available at: https://ccrma.stanford.edu/realsimple/aud_fb/Third_Octave_Filter_Banks.html (Accessed: 09 June 2023).

[3] Ritsch, Windried (no date) Imle, iemCloud. Available at: https://cloud.iem.at/index.php/s/oXcznxBe2TMmZbn?dir=undefined&path=%2FIAAI%2Fdoku&openfile=2966930 (Accessed: 16 June 2023).

[4] Selmer Varitone (no date) TCGAKKI. Available at: https://tcgakki.com/en/pages/selmer-varitone (Accessed: 16 June 2023).