Musical Instruments Classification (MusIC)

The action-research project MusIC (MUSical Instruments Classification) is a two-layer classificatory and descriptive infrastructure for musical instruments. It is designed to replace Hornbostel-Sachs as the default organological index while treating instruments as documents in the strict sense developed in documentation studies: not "texts," but material entities that become evidentiary and intelligible through regimes of making, custody, description, use, and transmission.

MusIC starts from the claim that an instrument is a sonic document: a durable epistemic entity in which multiple knowledges remain materially stored and retrievable under specific conditions. Instruments encode technical decisions, ecological constraints, repair and maintenance trajectories, authorization and restriction regimes, transmission structures (including exclusions and silences), and later institutional translations into catalogs, recordings, and museum descriptions. These are not ancillary "contexts"; they participate in what the artifact is as a document.

MusIC responds to the limits of Hornbostel-Sachs as an ad hoc, museum-centered commensuration device shaped within the institutional ecology of early twentieth-century European collecting and comparative musicology: a single tree designed to render heterogeneous artifacts comparable within collections, while lacking (i) a governed, logically consistent path of expansion and (ii) a formal structure for representing non-acoustical documentary dimensions as first-class, queryable entities.

MusIC therefore separates two functions that Hornbostel-Sachs collapses: addressability, the shared comparative indexing of sound-production mechanics, and documentary intelligibility, the formal representation of an instrument's epistemic thickness.

These two functions are implemented as two formally coupled layers. The MusIC Decimal Core (MDC) is a governed decimal tree that provides a stable, comparable address only for sound-production mechanics (e.g., vibrating medium; energy input regime; coupling mechanism; resonator/radiator configuration; optionally, mediation strictly as sonic generation). It is explicitly prohibited from encoding culture, territory, ritual, ownership, taboo, biography, transmission, or meaning. The MusIC Instrument Ontology (MIO) is a formally modeled layer (ontology plus facets, relations, and events) that represents the instrument as a document across territory and ecology as constraint systems; biological materials and provenance; permission and restriction regimes; repair and maintenance histories; activation conditions and norms; transmission structures; and institutional translation (recording, cataloging, classification assertions).

Every instrument record is governed by a strict binding rule: it receives exactly one primary MDC code as its default address for browsing and retrieval, and it may carry 0..n MIO assertions expressing its documentary reality. Hybrid instruments are handled without ad hoc subclassing: a hybrid receives one primary MDC code plus standardized secondary "also-has" codes for additional sound-producing subsystems, while the MIO represents hybridity explicitly through subsystem modeling and relations. This preserves index stability without forcing plural instruments into a single acoustic identity.

MusIC also formalizes five epistemic phases as event types attached to the instrument: material negotiation; making and adjustment; activation; learning and transmission; and explanation, capture, and institutional translation. Treating these phases as event-structure — not rhetorical framing — prevents phase 5 (institutional description) from masquerading as the instrument's total reality: classification, cataloguing, and recording are represented explicitly as translation operations, with agents, conditions, outputs, and characteristic omissions and losses.

In sum, the MDC maintains practical organological comparability, while the MIO preserves instruments as documents. MusIC is therefore not "a cleaner taxonomy" but a redesign of organological infrastructure: acoustic indexing remains possible without forcing sonic documents into a single museum-legibility regime.

This page will progressively host the system documentation: an overview of MDC levels, detailed tables, mapping notes, and worked examples.

This space is under construction. New content coming soon.