Replace the computer music instrument is not new

Today, to sound a digital piano as a real instrument, manufacturers must record and digitize all the notes of a real piano. A technique known as "sampling". If the idea is simple, the process, which uses sound samples ("samples" in English), is expensive and demanding in memory. Mathematicians of the school of engineers Insa de Toulouse took a radically different approach. Rather than ask the computer to replay pre-recorded notes, is making the sounds in real time. This was the Pianoteq project.

Because the main handicap of current software, used by all the composers who do not have the time or the means to use a real piano and a studio, it is burdensome. It should be at least 10 gigabytes to store the notes of the 88 keys on the piano, a note serious lasting up to a minute.

The sound in the equations

As digital pianos of the trade, they only have 32 or 64 megabytes of memory. Manufacturers have therefore resort to a trick, explains Philippe Guillaume, Director of the Department of mathematics of the Insa de Toulouse: "the memory of the digital piano stores only the attack of the note, or a few tenths of a second to the then loop using decreasing sound."

Replace the computer music instrument is not new. This means model as equations, the instrument and its environment. A complicated challenge. "When it strikes twice stronger on the sidelines of a piano, the sound is not only two times stronger, it is quite different and especially much richer harmonic acute" stresses Philippe Guillaume. A piano is the result of a multitude of phenomena: the strings vibration, resonance of the furniture, dissipation of acoustic energy in the air, room reverberation... It must also take into account the interaction (physicists speak of "coupling") between the strings and the air or the soundboard and air. Many additional equations.

A few years ago, a researcher at Inria, Patrick Joly, successfully model acoustic guitar its sound characteristics are quite close to those of a piano. Only problem, algorithms reproducing complex physical phenomena were so demanding in terms of computing power that it was impossible to operate the software in real time.

Tuner of pianos

Therefore, it took simplify equations neglecting certain parameters. This implies a serious collaboration between human art, musical instruments specialist and mathematician. With the Pianoteq project, it was the same individual. Because, in the mathematics on the later and to obtain a doctorate, Philippe Guillaume was for fifteen years... piano tuner: "Pianoteq project lasted three years." But it is the result of thirty years of experience as a piano tuner. "It has for example developed an original and"simple"way to model the coupling between the piano soundboard and strings. Indeed, this was the subject of a patent application. Technology has also greatly facilitated the things, including the arrival three years ago, processors operating at a clock frequency of 2 GHz, without whom this project would not have been possible.

Today, the Pianoteq software is marketed via the company Modartt (Models and Data for Arts and Technology). Sold on the Internet for some 250 EUR, the software is a small revolution in the world of music. "With Pianoteq, is between in the future", enthuses Rod Bowkett, English composer and one of the first users, that points still some defects. For example, the notes played with the pedal down does not sound properly. "What they did is amazing." "Today, I can work with a simple laptop and so travel light", said Sophia Morizet, in Los Angeles, composed music for Hollywood films. Modartt also hopes to entice manufacturers of digital pianos.