Design
The steli blades, the actual interface of this project, have been designed to convey an intuitive affordance to the players. The steli have been designed to suggest a garden of sounds.
In fact, the original idea was to use plastic grass blades…
…which then developed in the final steli in reason of a metaphore that was considered too explicit.
Sounds
Instruments. Steli are two installations which play two similar instruments, a glockenspiel and a vibraphone. The former, characterised by short and high pitched sounds, plays the melody, whereas the latter, characterised by longer and amplified sounds, makes the accompaniment.
These two instruments were chosen not only for their delicate sound but also for practical reasons: a percussive instrument was easier to build than wind instruments or strings. In addition, by giving less voltage to the solenoid (which is the actual element that plays the notes) the plate of the instrument (the source of the sound) can be played with a different force, according to how the stelo is touched.
How to play. Steli are waving musical instruments that play the sound of percussive ones. The gestures a musician is required to do when playing the original intruments differs considerably from those required for playing Steli.
Therefore, in order to achieve the most natural interaction possible, a careful series of studies was needed.
To play a stelo the user needs to bend it first: the more the stelo gets bent, the more it sounds. Once the stelo gets released, it starts to make its music, playing the note at every bounce while returning to its default position.
Scales. The two musical instruments are set on different scales. The glockenspiel plays the F scale, while the vibraphone the C scale. Most of the notes are in harmony, but some are not present in both scales. This feature allows musicians, if they would like to do so, to obtain a wider possibility of melodic expression.
Each blade plays one note only such as in a percussive instrument, where each plate corresponds to a precise note.
Volume. The volume is set by the intensity of bending. A gentle touch would result in a lower sound, whilst a hard touch would produce a louder one.
This effect is obtained by calculating the maximum bending of the blade in a given time (0,3 seconds), that is the speed, i.e. the intensity, of the movement.
This feature was developed after observing the same behaviour in percussive instruments.
Steli | Context | How to use it | Design & Sounds |
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