The Computer makes Music in Pisa
by Leonello Tarabella
The keywords characterising the activity of the Computer Music
laboratory of CNUCE-CNR, Pisa, are man-machine interaction and
real time gesture control. The computer interacts with the artist
to produce music in many different ways. In order to achieve this,
a special language called Real-Time Concurrent Pascal Music (RTCPM)
has been implemented. Using this language, a musical performance
can be defined in terms of many procedures running simultaneously
and interacting with the composition program during execution.
As an evolution of RTCPM, a new language named GALileo (Graphic/ALgorithmic)
which includes both visual programming and signal processing “facilities”
is now under development.
In order to create and control interactive live computer music/graphics
performances, the CNUCE Computer Music lab employs infra-red beams
and video captured image processing technologies for the remote
sensing of moving objects handled by performers or of gestures
made by them. The most important devices that have been developed
using this approach are:
- TwinTowers (in collaboration with IEI-CNR) - this system receives
information from the movement of the performer’s hands. It consists
of two sets of four infra-red sensing devices that create two
zones of the space (the vertical edges of two square-based parallelpipedon,
or towers) in which an object can be detected in terms of distance
and front and side rotations with respect to a reference frame.
The system thus implements a kind of double aerial tri-dimensional
joy-stick.
- Aerial-Painting-Hands - this system, developed by Giuseppe Scapellato
and normally used by the artist Marco Cardini (see Ercim News
No.35), detects the positions and movements of a performer’s hands;
the performer wears a pair of different coloured gloves and moves
his/her hands in a CCD camera video range. The signal is sent
to a computer which processes the images and recognises the x-y
positions of both hands and the open/close status of the right
hand. The computer then synthesizes in real-time coloured images
projected on a large video screen according to the movements of
the performer’s hands. While painting in the air, the performer
is also creating computer generated music in real-time An advanced
version of this system is now under development. The new system
will recognise the posture, rotation and position in space of
the hands, enabling the transmission of more sophisticated information
and thus a greater expressiveness during the perfomance.
- UV-stick - this system consists of a short straight stick (lit
by a UV lamp) and moved in the visual range of a CCD camera connected
to a computer which recognises the 2-D position and 3-D rotations
of the stick. The data acquired is used to manage sound synthesis
algorithms and create music in real-time.
- Imaginary Piano - where the hands of a performer play in the air
with no real keyboard in front of a camera, connected to a video
digitizer card. A special application running on the computer
recognizes the player’s gestures, interacts with a RTCPM program
and executes an external sampled piano sound.
The Computer Music Laboratory also participated in the EC ESPRIT
project CATS (Computer Aided Theatrical Score) for theatre and
cinema direction simulation.
For more information, see: http://spcons.cnuce.cnr.it/music/cmd.html
Please contact:
Leonello Tarabella - CNUCE-CNR
Tel: +39 050 593 276
E-mail: l.tarabella@cnuce.cnr.it
