Elements of technique and language for performing and composing with the digital musical instrument Karlax: Case study of Instrumental Interaction III for guitar and Karlax by Benjamin Lavastre
Presented by : Benjamain Lavastre
This presentation looks back on more than four years of experience in composition, performance, research, analysis and teaching with the Karlax digital musical instrument (DMI). The Karlax is a two-handed interface whose main sensors are ten continuous keys, eight pistons giving velocity indications, an inertial unit with three axes of accelerometers and gyroscopes. It also features a rotating axis at its center. Its design enables a large amount of control to be generated from simple gestures. Developed in the early 2010s, this MIDI controller has been praised for its design qualities, and draws on an active composer/performer community and extensive repertoire. This makes the Karlax an ideal candidate for a second, more in-depth phase with an DMI. Playing the Karlax or composing for this instrument requires a range of techniques and leads us to reconsider the place of instruments in musical practices. This presentation comments on a number of specific techniques, using concrete examples from the piece Instrumental Interaction III, and defines a framework for reflection around the definition of an instrumental identity, the place of gesture, interaction strategies and perception.
After more than 50 years' experience with digital musical instruments (DMIs) and the appearance of the first conclusive prototypes, notably Michel Waisvisz's The Hands instrument developed in the mid-1980s, several issues have been identified. Among these, the sound-gesture relationship constitutes a fundamental difference between digital and acoustic instruments. For acoustic instruments, this relationship is given by the physical behaviors of vibrating structures (e.g. strings, membranes, reeds or air columns, etc.). These structures vibrate in their own way, based on the properties of the materials. In other words, even if strings, reeds and membranes observe complex vibration patterns, these structures can only vibrate in a limited number of ways. These structures vibrate in their own way, based on the properties of the materials. In other words, although strings, reeds and membranes observe complex vibration patterns, these structures can only vibrate in a limited number of ways. The performer's gestures and the resulting sounds are, however, inextricably linked by physical laws. Digital musical instruments (DMIs), on the other hand, consist of an interface connected to a sound-generating device (e.g. a computer and speakers), the two being linked by applications (mapping) defining the relationship between the performer's gestures and the resulting sounds. For DMIs, the sound-generating algorithm determines the “vibrations” that the instrument produces. Also, the sound-gesture relationship is arbitrarily defined by the instrument designers, composers or performers. There is no inherent connection between the performer's actions and the resulting sound, which defines an unlimited number of possibilities for sound-gesture associations. The composers and performers of an DMI must then stage the desired sound result.
Furthermore, with regard to design and conception, DMIs must meet certain requirements such as robustness, stability, precision, reproducibility and rapid response (low latency). These design qualities must enable not only good control quality but also instrumental virtuosity. Finally, access to DMIs happens to be relatively restricted, with few instruments making it beyond the prototype stage. Also, most DMIs encounter difficulties in establishing themselves over time and are most often played by a single performer. Consequently, it is difficult to define, for a given instrument, the “habitus” of interpretation, composition and listening necessary for its evolution. It is therefore necessary to build a creative community around a “tried and tested” DMI. This can be based on a varied and demanding repertoire of pieces exploring several expressive facets, and tools facilitating interpretation and composition. The choice of instrument must also take into account the possibility of repairs (renewal of worn parts, replacement of sensors, etc.). Finally, compositional strategies must also anticipate issues related to the obsolescence of computing environments housing programming, mapping and sound synthesis.
With these observations in mind, this presentation focus on the Karlax and proposes several composition and performance strategies from the piece Instrumental Interaction III (Gatinet & Lavastre, 2024) notably data conditioning, playing techniques, mapping, types of sound synthesis, spatialization, programming and notation. For this composition project, we developed several aspects of writing that reflect the functioning of DMIs, such as parametric writing in the form of strata with different temporalities, the place of gesture both physical and musical, and the development of interaction strategies inspired by metaphors linked to computer music. This project has identified a number of key issues for the composition, performance and perception of a mixed piece with Karlax, involving current computer systems and significant control possibilities (real-time processing, multi-channel broadcasting system). These include the creation of the Karlax sound universe, the management of events throughout the piece, latency problems, the difficulty of making musical intentions perceptible through gestures, and the writing and control of spatialization. Finally, Karlax offers many interesting aspects for both composer and performer: the composer creates a sound and performance space by delineating difficulties and expressive potential, while the intermodal ambiguity of the couple gesture-sound offers a new layer of meaning.
The Karlax may correspond to the needs of a musician looking for an interface with high control quality that can be integrated into different contexts, particularly in interaction with acoustic musical instruments. So, what kind of society would the Karlax be an option for a composer, performer or listener? What updates to the interface and tools, and what repertoire, would be required? Karlax's place in the DMI landscape is unique and endowed with great potential, but the obstacles remain significant, particularly when it comes to reproducing pieces. With this in mind, this presentation uses the example of an interface to examine the role of instruments in contemporary musical creation.