A Very Fractal Cat, Somewhat T[h]rilled


This is the latest version of a series of algorithmic performance pieces for pianos, computer and “cat” that I started working on at the end of 2008 (the proverbial cat walking on a piano keyboard). The performer connects through a keyboard controller, four pedals and two modulation wheels to four virtual pianos both directly and through algorithms. Through the piece different note and phrase generation algorithms are triggered by the performer's actions, including markov chains that the virtual cat uses to learn from the performer, fractal melodies, plain scales and trills and other simple algorithms. The sound of the pianos is heard directly, and is also processed using spectral, granular and other synthesis techniques at different points in the performance, creating spaces through which the performer moves. A surround environment is created with Ambisonics spatialization, and everything in the piece (algorithms, sound generation and processing and graphical user interface) was written in the SuperCollider language.

See this paper for more details on the piece and its software environment.

(photo by David Kerr, Modulations 2.1)


Stereo reduction of a performance recorded in the Stage at CCRMA on December 18th 2009: OGG, MP3, WAV. Or a reduction to 5.0 surround (compressed) AC3. The original is an Ambisonics 3rd order encoded audio stream.


  • Shangai Conservatory of Music Concert, Shanghai, China, May 21, 2014
  • CCRMA Fall Concert, CCRMA Stage, November 29th, 2012.
  • SuperCollider Symposium 2010, "A Very Fractal Cat, Somewhat T[h]rilled", Kl. Wasserspeicher Concert, Berlin, September 24th 2010.
  • LIPM, "Un Gato muy Fractal", LIPM, Centro Cultural Recoleta, Buenos Aires, Argentina, August 27th 2010.
  • FLAMUC 2010, "Un Gato muy Fractal", ICPNA Centro, Lima, Perú, July 1st 2010.
  • LAC2010, Kikker Theater Concert, Utrech, May 3rd 2010.
  • Modulations 2.2, SOMArts, San Francisco, April 17th 2010.
  • A Cagian Musicircus, "A Very Fractal Cat, unCaged", CCRMA Concert, November 13th 2009.

    An extended version of “A Very Fractal Cat” was performed as a 30 minute music set in the CCRMA Stage (program notes)

  • Transitions, Summer Concert 2009, CCRMA, September 18th 2009.

    “A Very Fractal Cat, Somewhat T[h]rilled”, another performance of the “Fractal Cat” series of pieces for piano controller and computer algorithms. In this one the controller program was again extended with new algorithms and gestures. (program notes)

  • Modulations 2.1, The Compound, San Francisco, April 4th 2009 (pictures from the event).

    “A Very Fractal Cat”, performance piece for piano controller and computer processing and algorithms (program notes)

  • LAC2009 Concert (Linux Audio Conference 2009), Parma, Italy, April 16th 2009.

    Short excerpts from the performance are currently part of the demonstration of the "Sala Bianca" in Casa del Suono, a Wave Field Synthesis room (Parma, Italy).

  • Fall 2008 CCRMA Concert, the Stage, November 20th, 2008.

    “Cat Walk”, this is the first performance of the series of pieces for piano controller and computer. At this time only a few algorithms were implemented in the software and the spatialization was done statically and through amplitude panning.

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