Cthulhu: The Cosmic Abyss presented a fundamental question: what does cosmic horror sound like in 2053, when humanity has reached the stars but the abyss has been waiting since before time began?

The answer required building a sound world from scratch. Every element of the orchestral score was performed live. No sample libraries, no synthetic substitutes. The Budapest Scoring Orchestra was recorded in dedicated sessions; the choir, numbering around twenty singers, was recorded separately in Budapest during its own session. The strings became the emotional backbone of the score, moving between melodic themes and oppressive, suffocating textures depending on the dramatic context.

Tina Guo performed the theme of Noah, the game's protagonist, on electric cello. A deliberate choice over classical cello: the slight rawness of the instrument gave Noah's identity an edge of fragility and impurity that felt right for a character descending into madness.

Beyond the orchestra, the score required sounds that had never existed before.

A sealed metal barrel filled with water. Inside it, a hermetically sealed box containing a digital recorder. Microphones placed at the exterior. The barrel was struck, scraped and bowed with different mallets and objects of varying materials. This became the sonic language of the underwater exploration sequences: organic, pressurized, alive.

The carnyx — a bronze war horn of the Iron Age Celts, dating to around 200 BC, its bell sculpted into the gaping head of an animal, designed to terrorise enemies on the battlefield — was recorded and woven throughout the entire score as a subliminal thread. Its presence is felt before it is consciously heard, embedding a call of ancient dread beneath every scene from the very beginning of the game.

A dudukwas recorded and processed through Loris resynthesis, a spectral analysis and reconstruction technique that transformed the instrument's breath and timbre into something unrecognisable yet deeply human. This became the sound of humanity's decline: performed live via the ContinuuMini, a rare continuous controller that allowed real expressive gesture rather than programmed sequences.

The Osmosesynthesizer was used exclusively as a performance controller, feeding expressive touch-sensitive data into synthesis engines, with every result captured as live audio. No synthesizer sound on this score was programmed. Each was performed.

Additional acoustic layers were built from instruments chosen for their ancient and unfamiliar resonance. A zither, played with mallets. A guqin, bowed with an archery bow rather than plucked, its strings vibrating in a way the instrument was never designed for, producing a brittle and unsettling tone. A Gembri G3 (luthier Philippe Berne) grounds the R'lyeh sequences in something earthen and organic. A citole à archet (also by Philippe Berne), a medieval instrument repurposed for bowed playing, produces a raw, not always beautiful sound that felt honest to the nature of the horror. A didgeridoo, performed by my son, adds subharmonic drone to the deeper sequences.

The choral writing served two distinct functions: atonal whispered effects on one hand, and the full epic weight of voices in unison on the other. My own voice was recorded sixteen times in overlapping layers of incomprehensible whispered fragments, woven into the texture to evoke the dreaming minds players encounter throughout the game. A subliminal undercurrent of encroaching madness.

The guiding vision was a world that feels slightly futuristic but deeply organic, where even the electronic instruments were performed and recorded as human gestures, and where the listener is never quite certain whether what they hear is ancient or contemporary, natural or constructed.

The score does not describe R'lyeh. It inhabits it.