@prefix skos:    <http://www.w3.org/2004/02/skos/core#> .
@prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix lv2:     <http://lv2plug.in/ns/lv2core#> .
@prefix pu:      <http://purl.org/stuff/plugin-universe/> .
@prefix pucat:   <http://purl.org/stuff/plugin-universe/category/> .

## Plugin Universe category scheme
##
## The taxonomy this catalogue sorts plugins by. A SKOS concept scheme, not an
## OWL class hierarchy: these are subject headings, and a plugin belongs to
## several of them without that meaning anything about its type.
##
## This file is the source. It used to be a JavaScript object literal inside
## PluginSerialiser.js holding nothing but parent links, which is why the scheme
## in the store had four predicates and no way to say what a category meant or
## what it was called elsewhere.
##
## Three things are recorded here that a bare hierarchy cannot hold:
##
##  - **skos:altLabel** — what a person might type instead. These feed the
##    lexical signal, so searching "reverberation" or "echo" reaches the same
##    plugins as "reverb" or "delay". They are deliberately words a *user*
##    would use, not synonyms in the abstract.
##  - **skos:definition** — the boundary. Categories are assigned by mapping
##    from vendor tags and LV2 classes, and the mapping is only reviewable if
##    somebody wrote down what the target means.
##  - **skos:closeMatch** — the same idea in someone else's vocabulary, which
##    is what lets an LV2 bundle's own class be honoured rather than discarded.
##
## On the LV2 alignments: every lv2: class named here was verified against the
## LV2 plugins installed on the development machine. Classes that sound right
## but were not attested are not asserted — `lv2:EffectPlugin` in particular
## appears in some bundles in the wild and is not in the set that could be
## confirmed, so `pucat:effect` has no LV2 match rather than a guessed one.
##
## On AUFX-O: vocabs/alignment.ttl maps this project's *structure* to AUFX-O and
## deliberately stops at terms that could be confirmed. Effect-type alignment
## (aufx: equivalents of reverb, delay, and so on) is not asserted here for the
## same reason and is left for a pass that can check the published ontology.

pu:categories a skos:ConceptScheme ;
    rdfs:label "Plugin Universe categories" ;
    dcterms:description "Subject headings for audio plugins, mapped from vendor tags, LV2 plugin classes and curated roles." ;
    dcterms:license <https://creativecommons.org/publicdomain/zero/1.0/> ;
    skos:hasTopConcept pucat:effect , pucat:instrument , pucat:utility , pucat:midi , pucat:guitar .

## ── Top concepts ────────────────────────────────────────────────────────────

pucat:effect a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:topConceptOf pu:categories ;
    skos:prefLabel "effect" ;
    skos:altLabel "fx" , "audio effect" , "processor" , "insert" ;
    skos:definition "Processes an incoming audio signal. The complement of an instrument, which generates one." .

pucat:instrument a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:topConceptOf pu:categories ;
    skos:prefLabel "instrument" ;
    skos:altLabel "virtual instrument" , "sound source" , "vsti" , "sound generator" ;
    skos:definition "Generates audio, usually in response to notes. The complement of an effect." ;
    skos:closeMatch lv2:InstrumentPlugin .

pucat:utility a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:topConceptOf pu:categories ;
    skos:prefLabel "utility" ;
    skos:altLabel "tool" , "helper" , "routing" , "housekeeping" ;
    skos:definition "Does a job in the signal path without being heard: routing, gain staging, format conversion, metering." ;
    skos:closeMatch lv2:UtilityPlugin .

pucat:midi a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:topConceptOf pu:categories ;
    skos:prefLabel "midi" ;
    skos:altLabel "midi effect" , "note effect" , "midi processor" ;
    skos:definition "Operates on notes and control messages rather than on audio." ;
    skos:closeMatch lv2:MIDIPlugin .

pucat:guitar a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:topConceptOf pu:categories ;
    skos:prefLabel "guitar" ;
    skos:altLabel "pedal" , "stompbox" , "cabinet" , "guitar effect" ;
    skos:definition "Built for electric guitar or bass: amp and cabinet simulation, and the pedal-shaped effects that go with them." ;
    skos:related pucat:amp , pucat:distortion .

## ── Effects ─────────────────────────────────────────────────────────────────

pucat:dynamics a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "dynamics" ;
    skos:altLabel "dynamic range" , "gate" , "expander" , "envelope shaper" ;
    skos:definition "Changes level as a function of level: compression, limiting, gating, expansion." ;
    skos:broader pucat:effect ;
    skos:closeMatch lv2:DynamicsPlugin .

pucat:compressor a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "compressor" ;
    skos:altLabel "compression" , "comp" , "bus compressor" , "glue" ;
    skos:definition "Reduces dynamic range by attenuating signal above a threshold." ;
    skos:broader pucat:dynamics ;
    skos:related pucat:limiter ;
    skos:closeMatch lv2:CompressorPlugin .

pucat:limiter a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "limiter" ;
    skos:altLabel "limiting" , "brickwall" , "maximiser" , "maximizer" ;
    skos:definition "Compression at a ratio high enough that the output does not exceed a ceiling." ;
    skos:broader pucat:dynamics ;
    skos:closeMatch lv2:LimiterPlugin .

pucat:reverb a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "reverb" ;
    skos:altLabel "reverberation" , "hall" , "room" , "plate" , "spring" , "convolution" , "ambience" , "space" ;
    skos:definition "Simulates the reflections of a space, real or invented." ;
    skos:broader pucat:effect ;
    skos:related pucat:spatial ;
    skos:closeMatch lv2:ReverbPlugin .

pucat:delay a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "delay" ;
    skos:altLabel "echo" , "tape delay" , "ping pong" , "slapback" ;
    skos:definition "Repeats the signal after a measured interval, usually with feedback." ;
    skos:broader pucat:effect ;
    skos:related pucat:reverb ;
    skos:closeMatch lv2:DelayPlugin .

pucat:distortion a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "distortion" ;
    skos:altLabel "overdrive" , "fuzz" , "drive" , "clipping" , "bitcrusher" ;
    skos:definition "Adds harmonics by non-linear processing, from gentle colouration to deliberate destruction." ;
    skos:broader pucat:effect ;
    skos:closeMatch lv2:DistortionPlugin .

pucat:saturation a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "saturation" ;
    skos:altLabel "warmth" , "tape saturation" , "analogue warmth" , "analog warmth" , "exciter" , "harmonic exciter" ;
    skos:definition "Distortion mild enough to be heard as colour rather than as an effect — tape, tube and transformer emulation." ;
    skos:broader pucat:distortion ;
    skos:closeMatch lv2:WaveshaperPlugin .

pucat:modulation a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "modulation" ;
    skos:altLabel "chorus" , "flanger" , "phaser" , "tremolo" , "vibrato" , "lfo" ;
    skos:definition "Varies a parameter over time, usually pitch or delay, usually periodically." ;
    skos:broader pucat:effect ;
    skos:closeMatch lv2:ModulatorPlugin .

pucat:eq a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "eq" ;
    skos:altLabel "equaliser" , "equalizer" , "tone control" , "shelf" , "parametric" ;
    skos:definition "Adjusts level per frequency band." ;
    skos:broader pucat:effect ;
    skos:related pucat:filter ;
    skos:closeMatch lv2:EQPlugin , lv2:ParaEQPlugin , lv2:MultiEQPlugin .

pucat:filter a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "filter" ;
    skos:altLabel "lowpass" , "highpass" , "bandpass" , "cutoff" , "resonance" , "wah" ;
    skos:definition "Attenuates part of the spectrum, typically with a movable cutoff and resonance." ;
    skos:broader pucat:effect ;
    skos:related pucat:eq ;
    skos:closeMatch lv2:FilterPlugin , lv2:LowpassPlugin , lv2:HighpassPlugin , lv2:BandpassPlugin .

pucat:spatial a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "spatial" ;
    skos:altLabel "stereo" , "panner" , "imaging" , "width" , "surround" , "binaural" ;
    skos:definition "Places or widens a signal in the stereo or surround field." ;
    skos:broader pucat:effect ;
    skos:closeMatch lv2:SpatialPlugin .

pucat:amp a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "amp" ;
    skos:altLabel "amp sim" , "amplifier simulation" , "cabinet simulation" , "head" , "combo" ;
    skos:definition "Simulates a guitar or bass amplifier and its cabinet." ;
    skos:scopeNote "Not lv2:AmplifierPlugin, which means a gain stage — a false friend worth stating, since the names match and the meanings do not. lv2:SimulatorPlugin is the closer LV2 class." ;
    skos:broader pucat:guitar ;
    skos:closeMatch lv2:SimulatorPlugin .

## ── Instruments ─────────────────────────────────────────────────────────────

pucat:synth a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "synth" ;
    skos:altLabel "synthesiser" , "synthesizer" , "subtractive" , "fm" , "wavetable" , "additive" ;
    skos:definition "Generates sound from oscillators or algorithms rather than from recordings." ;
    skos:broader pucat:instrument .

pucat:granular a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "granular" ;
    skos:altLabel "granular synthesis" , "grain" , "texture" ;
    skos:definition "Builds sound from many short fragments of a source." ;
    skos:broader pucat:synth ;
    skos:related pucat:sampler .

pucat:sampler a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "sampler" ;
    skos:altLabel "sample player" , "rompler" , "sample library" , "soundfont" ;
    skos:definition "Plays back recorded audio, mapped across pitch and velocity." ;
    skos:broader pucat:instrument .

pucat:generator a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "generator" ;
    skos:altLabel "tone generator" , "noise" , "signal generator" , "test tone" ;
    skos:definition "Produces a signal without being played: tones, noise, test signals." ;
    skos:broader pucat:instrument ;
    skos:closeMatch lv2:GeneratorPlugin , lv2:OscillatorPlugin .

pucat:drums a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "drums" ;
    skos:altLabel "drum machine" , "percussion" , "beat" , "kit" , "808" ;
    skos:definition "Drum and percussion instruments, whether sampled or synthesised." ;
    skos:broader pucat:instrument .

pucat:bass a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "bass" ;
    skos:altLabel "bass guitar" , "sub" , "bassline" , "808 bass" ;
    skos:definition "Instruments for the bass register, sampled or synthesised." ;
    skos:broader pucat:instrument .

pucat:piano a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "piano" ;
    skos:altLabel "keys" , "electric piano" , "rhodes" , "wurlitzer" , "keyboard" ;
    skos:definition "Piano and electric piano instruments." ;
    skos:broader pucat:instrument .

pucat:organ a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "organ" ;
    skos:altLabel "hammond" , "drawbar" , "tonewheel" , "leslie" ;
    skos:definition "Organ instruments, and the rotary speakers that go with them." ;
    skos:broader pucat:instrument .

## ── Utility and MIDI ────────────────────────────────────────────────────────

pucat:analysis a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "analysis" ;
    skos:altLabel "analyser" , "analyzer" , "spectrum" , "meter" , "metering" , "oscilloscope" , "tuner" , "loudness" ;
    skos:definition "Measures and displays the signal without changing it." ;
    skos:broader pucat:utility ;
    skos:closeMatch lv2:AnalyserPlugin .

pucat:mixing a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "mixing" ;
    skos:altLabel "mixer" , "bus" , "console" , "summing" ;
    skos:definition "Combines or routes several signals." ;
    skos:broader pucat:utility ;
    skos:closeMatch lv2:MixerPlugin .

pucat:sequencer a skos:Concept ;
    skos:inScheme pu:categories ;
    skos:prefLabel "sequencer" ;
    skos:altLabel "step sequencer" , "arpeggiator" , "arp" , "pattern" , "euclidean" ;
    skos:definition "Generates note sequences rather than notes played by hand." ;
    skos:broader pucat:midi .