First performed in 1999, Gran Cassa is later presented in a new version for a special innovative instrument designed by the author: the feed-drum. This instrument, called "feed-drum" precisely for its intrinsic capacity of transforming sound, responds to both the velocity and the direction of the performers' gestures. Each type of sound is correlated to the type of gesture that produces it, to the distance travelled by the hand of the performer and to the speed with which the hand moves across the different areas of the membrane. In Gran Cassa (bass drum) the live sound represents a separate entity with which the performer interacts. It is an unusual relationship in which the movements of the performer affect the vibration of the drum.
The feed-drum is an innovative electroacoustic instrument designed by Michelangelo Lupone for his multimedia work, Feedback. It is quite a large drum, composed of a membrane with a vibrational map drawn on its surface, a steel resonator and a loud speaker. The feed-drum is based on the principle of the "feedback" of the sound signal. For the first time it enables the musician to select and control the complex vibrational modes of the membrane, both in mono and stereophonic modes, by means of particular techniques. Sound, produced by the action of the musician by percussion, pressure or friction, selects on the surface of the membrane one or more nodes (like a string instrument) which produces one or more pitches and timbres. Differently from a string, which might be considered harmonically mono-dimensional, the membrane varies its vibrational modes in two dimensions; this implies the use of a new technique of performance, since the generated frequencies are not harmonics but follow a non-linear behaviour.
An important feature of the feed-drum is that the tones generated by the instrument can be varied in amplitude and also held indefinitely by the musician, exceeding the short-time duration limit of the sounds of conventional percussion instruments. The feed-drum was produced by Istituto Gramma in collaboration with CRM - Centro Ricerche Musicali and Art Mama Factory and was premiered on the occasion of the 2002 "Musica Scienza" Forum.