This paper presents the GrooveTransformer, a Eurorack module designed for generative drum sequencing. Central to its design is a Variational Auto-Encoder (VAE), around which we have designed a deployment context enabling performance through accompaniment and/or user interaction. This module allows the user to use the system as an accompaniment generator while interacting with the generative processes in real-time. In this paper, we review the design principles and technical architecture of the module, while also discussing the potentials and short-comings of our work.

This paper investigates GrooveTransformer, a real-time rhythm generation system, through the postphenomenological framework of Variational Cross-Examination (VCE). By reflecting on its deployment across three distinct artistic contexts, we identify three stabilities: an autonomous drum accompaniment generator, a rhythmic control voltage sequencer in Eurorack format, and a rhythm driver for a harmonic accompaniment system. The versatility of its applications was not an explicit goal from the outset of the project. Thus, we ask: how did this multistability emerge? Through VCE, we identify three key contributors to its emergence: the affordances of system invariants, the interdisciplinary collaboration, and the situated nature of its development. We conclude by reflecting on the viability of VCE as a descriptive and analytical method for Digital Musical Instrument (DMI) design, emphasizing its value in uncovering how technologies mediate, co-shape, and are co-shaped by users and contexts.