HighC is inspired by Iannis Xenakis' UPIC work of the mid 80's. Contrary to most other "audio paint" systems, HighC uses a structured (additive) synthesis model. This allows composing elementary sound objects into higher level elements, and manipulate them symbolically. Roughly said, HighC is to HyperUpic and its descendants what PowerPoint is to Photoshop.

Graphical audio synthesis and upic

Iannis Xenakis (1922-2001) was an architect and a composer who envisioned a novel way to create music in the 1970's. His system, called UPIC, for "Unité polyagogique informatique du CEMAMU", used a graphics tablet and a fairly expensive computer.

The concept behind HighC and UPIC, what I call "graphical audio synthesis", is very simple and powerful. An audio composition is represented as a set of marks on a score sheet, where the horizontal position and span of the mark represent the time at which they occur and the vertical axis represents the evolution of their pitch. In a way, it extends and generalizes traditional music notation by making scores continuous and drawn in a linear space. An illustration explains this concept much better: below is the score of Mycenae Alpha, one of the first pieces created with UPIC:

The beauty of graphical audio synthesis is that it is usable by the most novice musicians, even children, and still it provides a huge expressive space for the most creative and demanding composers. Anybody can start creating their own compositions in HighC or UPIC in a matter of seconds. Confirmed musicians are offered new ways to explore soundscapes, literally to "create the unheard", which is the essence of all artistic endeavor.

Yet, below the apparent simplicity of the concept lie a number of issues and compromises to ponder over. The implementation of the synthesis technique is quite trivial for anyone knowledgeable in digital audio processing. The first issue I call the "representation" problem: First of all, a simple sound is not simply a trajectory of pitch in time. A sound has other evolving attributes, such as its intensity and timbre. For a faithful representation to be provided, those attributes should be encoded in the visual image of the soundscape. Second, because our visual and auditory systems have very different ways of composing elementary signals to give them a meaning, any visual representation of audio is doomed to miss something of the audio stimulus, or to create a perceptual distortion. As an example, I believe the main weakness of the current approaches is that they do not reflect the harmonic properties of sound: 2 sounds separated by approximately an octave look quite the same on the score, but they sound very differently depending on whether they are at unison or separated by a 7th or 9th.

Still, UPIC encountered much enthusiasm and was used by numerous contemporary music composers in the 80's and 90's despite its limited availability. Despite newer versions being written, the software-only UPIC has not been widely distributed and is not maintained anymore. Still, the CCMIX continues to maintain and evolve Iannis Xenakis' musical vision nowadays. Fortunately, thanks to nowaday's progress in computing power, massive additive synthesis, at the heart of UPIC and HighC synthesis models, is now available to a large audience on commodity hardware, with far more features and ease of use.

Organic vs. symbolic graphical audio synthesis

UPIC has inspired quite a few other interesting tools, such as HyperUpic and its heirs: Metasynth and Coagula (or try at Unesco). Yet, somehow, the most successful of those inheritors are bitmap-based rather than vector-based as was the original UPIC: the image is interpreted as a sonogram which is turned into a sampled sound by means of some kind of inverse Fourier transform. This synthesis technique provides very good means to literally chisel audio objects, add or remove effects at a very fine granularity. This technique definitely has its uses, and all those programs are great tools in the hand of capable musicians or even amateur to "create the unheard".

One of the key specificities of HighC over a few of these counterparts is that it is a symbolic system rather than an organic synthesis system. In HighC (as in UPIC), a piece is made of sound curves, and each curve is an individual object with its own properties, all numerically described. The composition is not an organic bitmap from which the acoustic phenomena emerge through a unique transformation. Simply said, HighC is to HyperUpic what MS PowerPoint is to Adobe Photoshop, or what Meccano is to Plasticine.

This has one drawback, namely that the representation of the auditory experience is not completely truthful ; it leaves room for interpretation. For instance, a sound with a noise waveform will be heard exactly the same whatever the pitch at which you place it.

However, I believe it is interesting to keep the ability to manipulate sounds as symbols: it lets you introduce the power of language (or assembly of symbols organized by rules) into your music creation activity. By "power of language", I mean that HighC makes it possible to create and manipulate higher level abstractions made of low level sound components, and combine them with each other transparently into even more sophisticated compositions.

It turns out, it is the essence of music composition to create such abstractions from raw acoustic events and combine them according to one's whim into more complex structures. Whether or not music is a language is a debate I won't enter into. In any case, HighC lets you create a language to manipulate sound, rather than propose you a single method for chiseling into a glob of sound.

The goal of HighC is to integrate this musical-language-building approach into a graphical audio composition tool.

The HighC approach over representational and structuring dilemma

I was lucky enough to do a month-long internship in 1984 as a high school student to experiment with UPIC. The concepts behind this instrument, most notably its ability to create a sense of synesthesia have kept fascinating me, as I think they reveal a lot of insights on what human computer interaction is about: transforming objects made of bits into representations made of atoms and vice-versa.

My own specialty is not music, but human-computer interaction, or, as I'd rather call it, interactive information systems design. The area of audio-painting/drawing raises numerous challenges, issues and compromises about representation, structuring and manipulation vocabularies, where I can put my experience at play.


HighC represents my solution to the representational and structuring dilemma I mention above. The software is still far from what I envision currently, and my vision still needs to be elaborated and explicated. A newer version of this page should fill the gap to explain the choices made here.


I started working on my own sound synthesis algorithms in 1991, had an extensive work phase in 1998 to polish up the model. I finally started writing a user interface to create music by drawing it in 2006. Version 1 was released in March 2007, and presented at IRCAM in June. In November 2007, version 1 had reached 10000 downloads, a sure mark that some interest is being raised. Still, the present version is only a sketch: it needs a lot of polishing and user testing to become a real instrument, and there are many more features that I intend to implement over the next few years to provide better control of the sounds, their dynamics, modulation and spatialization.

In releasing a partially featured version, my intend is to gather useful feedback early on, rather than deliver too complex a software that would not satisfy important requirements.

If you know how to use a drawing program, you'll know how to use HighC. I wish readers to try out HighC, and report on their uses on the forums.

Last, but not least, HighC is pronounced with a strong French accent: "I see!".


PS: I should add a few references here. I recommend reading Pierre Couprie's work, among which: "Graphical representation: an analytical and publication tool for electroacoustic music" or in French: La musique �lectroacoustique : analyse morphologique et repr�sentation analytique.