interius/exterius is a striking new addition to the evolving catalog of Berlin-based composer Catherine Lamb, whose deep explorations of harmony, temporality, and collective resonance have made her a defining voice in contemporary experimental music. Developed through a close collaboration with New York's Ghost Ensemble, this long-form chamber nonet unfolds through finely calibrated tuning, deep listening, and continually shifting sonic intention. The work's title reflects its central organizing principle: tones move in "interior" and "exterior" directions, shifting between inward balance within the ensemble and outward expansion towards new harmonic possibilities. The result is a piece that is simultaneously precise and open, crystalline and fluid -- attuned to the interplay between individual agency and collective form. Scored for flute, oboe, accordion, viola, cello, four- and five-string contrabasses, harp, and hammered dulcimer, the work investigates how collective intentions or focal points allow various and sometimes unusual sonic pathways to emerge in an ensemble context. In an "interior" direction, tones balance inward, reinforcing the equilibrium of the collective, while in an "exterior" direction, tones radiate outward, inviting subtle changes in texture and a broader field of interaction. This interplay of interiority and exteriority extends beyond dynamics or articulation. interius/exterius took shape over a series of intensive workshops between composer and ensemble, supported in part by Chamber Music America's Classical Commissioning Program. The harmonic material of interius/exterius is derived entirely from the harmonic series of a theoretical 10Hz fundamental -- an inaudible frequency whose overtones define a resonant, interlocking lattice of sound. This base-10 tuning system allows every pitch to be understood in relation to its spectral position, creating a shared harmonic language among the performers. Ghost Ensemble's performance reveals the otherworldly sonorities that arise from this structure, as shifting alignments, phasing relationships, and gradual timbral transformations guide the music's unfolding. Lamb's compositional language is deeply shaped by her studies with composer James Tenney and Dhrupad musician Mani Kaul, as well as her ongoing engagement with microtonal performance practice. Her interest in musical perception and psychoacoustics positions interius/exterius as both an inquiry into the nature of harmonic space and a lived experience of collective attunement. Ghost Ensemble -- known themselves for championing the work of Pauline Oliveros -- are perhaps, then, ideal collaborators, bringing both profound sensitivity and intuitive fluency to Lamb's music. With interius/exterius, Lamb and Ghost Ensemble have achieved a collaborative work of rare clarity and conceptual depth -- simultaneously precise and open, crystalline and fluid, exquisitely attuned to the interplay between individual agency and collective form.
