Elephant Heart is both an instrument and musical score at the same time. It is an alternative way of music notation and can therefore be seen as a “composition machine”.
The setup includes a conveyer belt, which functions as the score and conveys small marbles as notes. At the end of the belt, the marbles fall down and hit tuned metal tubes, which functions as the sounding part of the installation – the “Tubephone Campignon”.
The instrument is played by three performers: “Tempo”, “Rhythm” and “Pitch”. The Tempo player conducts the tempo by controlling the belt, so it either rolls slow or fast. The Rhythm player installs the marbles on the belt following rhythmical patterns according to the colours of the belt. The Pitch player turns the “Tubephone” so that each falling marble makes a sound in a different pitch.
The delay between installing the marbles and the actual sound, exhibits a spot in between composition and improvisation: The performers interact on each others actions, showing each others and the audience what music they can expect at the end of the belt. As the music actually is played it is too late to react. The performers have to be one belt-length ahead of the music.
Other compositions are fixed and expressed with a series of graphical scores. The colours and shapes of these scores correspond to those of the belt and “Tubephone”.
The instrument and the exhibition of it has two purposes:
1. As an exhibited installation where the audience can experience and play the instrument themselves in order to realize the inner structure of the musical limitations the instrument give.
2. As a performance where the audience can listen to virtuoso compositions played by the three performers.
The tuning of the “Tubephone” is a 19-tone circular system based on chains of minor thirds rather than chains of fifths used in the circle of fifths. It is similar to the 34-tone scale described by Larry Hanson (1994).
In 2011 a new version of the instrument was produced with motors of rotating wires, which are hitting the tubes of the “Tubephone”. This enables the instrument to play compositions with sustained tones. The motors are controlled via a wireless based computer interface that shows a virtual conveyer belt. The new version explores the duality of the virtual belt and the real physical belt and the different possibilities of the two worlds.