An Experimental System for the Synthesis of Chaotic Signals

 

• The interest for particular non-linear processes and affirmation according to which specific configurations of music can, in certain conditions, be attributed to interactions between irreducible unit of a dynamic system, has conducted to the realization of an electronic analog system for the experimentally verification of the chaos. More particularly it is a system based on classic Chua’s Circuits, for low frequency application. His compositional approach concerning to the evaluation of dynamic characteristics of the sounds of chaos: the turbulence phenomena and the pattern emerging from the phase space, towards a “road to chaos”. The chaotic synthesizer, in this first step, is based on a linear coupling of Chua circuits  for an experimentally verify the aspect of synchronization of complex dynamic systems.
• The system was simulated in PSpice and was built an prototype for a first musical composition named “Experimentation on chaotic interactions – Part I”
• As a development is provided the digital control of the analog system, through a digital interface in Arduino and a control software in Processing, for serial communication and GUI. The advantages are that the control parameters can be more accurate and can be created automation functions for a compositional score.

Electrodynamic loudspeaker drivers

• Building for the work “Piccolo Infinito” by Massimo Scamarcio and Neal Peruffo, in occasion of the event “Illuminazione” at the Palace of Arts of Naples (PAN).
• The installation was prepared in an elevator covered with black panels. With light wood trying to lose perception of the delimitation of space, accompanied by the diffusion of reverberated sound. The recorded sound (noise of the movement of the elevator) is propagated through special speakers that vibrate the metal walls.

http://www.comune.napoli.it/flex/cm/pages/ServeBLOB.php/L/IT/IDPagina/20133

OMC v011

• A timer applet for the execution of ”Sculpture Musicales” (John Cage) with Dario Sanfilippo (computer), Salvatore Carannante (electroacoustic feedback), Chiara Mallozzi (cello), writer (GSC2), at Castel Sant’Elmo, Naples (tribute to Cage 9/12/2012):

• http://elettroacustica.pbworks.com/w/page/23151328/SPAM%20start%20page

• http://criticaclassica.wordpress.com/2012/12/07/domenica-9-dicembre-lassociazione-alessandro-scarlatti-dedica-una-giornata-a-john-cage/

• Analysis of the problem: the implementation requires N different timbres playing together with attacks, durations and pauses openly predetermined. To guarantee the synchronization of executions need a timer to program the timings and sounds parameters. The OMC (Object Muiscale Cage) program, therefore, keeps track of the sculpture to be executed, its duration and pauses provide the countdown, time remaining, name of actual sculpture and dynamics. Is possible to create an Android applet.

Xen v0.2

• A new version of the program for computation of the probabilities transition table (MPT) formalized by Xenakis in the composition “Analogique AetB“, in addition to a optimization algorithm for the granualr synthesis in C-Sound. The program written in processing (with support of Java syntax) and can be used for manually input of the protocol of screens, with letters in [A, H] (for a historical reconstruction), or it is possible simulate the “Xenakis mechanism” provided: Equilibrium states, perturbation1-2, (E, P0, P1). The result of the process is writing in a .csd  file (alternatively is possible make the DSP in processing or use the OSC connection with SuperCollider server) therefore for the synthesis running need just make a render from C-Sound GUI.
• For the state oscillation p1 has been used the arbitrary statistical distribution algorithm for implement the P(X) indicated by Xenakis in literature.

Simple Audio Input Meter

• A very simple meter/waveform analyzer of sounds from the mic input of the sound card. The software is written in Processing lenguage and has been tested on Win 7 with Java 7 build 1.6.0_31-b05. Write me if you want the softwre (with changes and improvements).

Program for the computation of a Xenakis stochastic process

• Software reconstruction of Xenakis’ MPT (Transition probability matrix) Algorithm. The Stochastic Process consists of a Markov chain with a first-order explicit MPT and represents a process without memory. Various studies on the generation of pseudo-random distributions, Random Walks, Brownian motion and MPT have been made in C/C++ algorithms. In this case instead presents a program written in processing which allows to create a score of notes for a simple granular instrument in C-Sound. The notes consist in parameters for the granular  synthesis according to the screens suggested by Xenakis in Analogique B. The work is in beta versione but will be completed soon.
• The C-sound instrument uses a single granulator where the regions parameters are passed in  score. To this is more computational flexible respect to use n-granulators in parallel for each region, for each screen. However, the synthesis process, for each Δt = 0.5sec, repeats the same statistical distribution, and this periodicity does not correspond to originally construction by Xenakis. This problem must be solved in next version of program and .csd, or in DSP stand-alone application.

Research on Consonance Timbre

• We present a simple didactical approach, suitable for the students, which allows to illustrate and test some basic features of the concepts of timbre and consonance of musical sounds, in the context of western tonal music. This approach will be embedded in web documents to be remotely accessed by students and teachers. We will say that two pure sounds, separated by a given frequency interval, are consonant if their simultaneous emission produces a gratifying effect; dissonant, on the contrary, when the effect is disagreable. This gross criterion is based on psychoacoustical considerations. We know that the human auditory apparatus is able to distinguish the sounds produced by a saxophone and a clarinet when the same note with the same pitch and the same loudness is played with these musical instruments. To justify this phenomenon we simply say that this ability depends on a characteristic of sounds called timbre. But what the timbre of a sound is? Even if many papers and books have been written about this very fascinating question, we are still very far from a scientific exhaustive definition of it. The main characteristics of the timbre of sounds of a musical instrument are usually considered their harmonic content, attack and decay. In this paper we will limit ourselves to examine mostly the harmonic content, because it can be considered like a footprint of a musical sound and seems to play a relevant role in the explanation of consonance of sounds, particularly in western tonal music. In this context we will specially point out some important contributions given by H.H. Helmoltz, J.P. Rameau and by the modern psycoacoustics.

http://www.risma.unina.it/

http://www.fisica.unina.it/mfa/acust/

Instructions to program installation:

Download and install the Pure Data Extended platform: http://puredata.info/downloads/pd-extended Download the package: timbreAnalyzer_v0.4_documentazione_del_software.rar and unzip the folder in the path C:\Program Files, Remove the subfolder “pnf” and paste it into C:\, at end open the program timbreAnalyze_v04.pd. It is recommended to see the software documentation