{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.fourth","code":"thing-q267984","url":"https://ver.cy/models/thing/q267984/","name":"fourth","alternateNames":[],"kind":"thing","status":"research-draft","version":"0.2.0-wave.4","language":"en","classifiers":{"family":"Thing Registry","category":"","entryKind":"","plane":"","domain":["XCT.TME"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"In music, a fourth is an interval spanning four notes of a scale, such as from C up to F; the registry aliases name its qualities, including the perfect fourth and the augmented fourth, also called the tritone. The fourth is a basic interval in harmony and melody, and its exact size in semitones depends on its quality, so the quality should be identified. This is the musical sense, distinct from the ordinal fourth in a sequence.","purpose":"Let an agent explain the musical fourth, relay its qualities and role from music-theory sources, describe the qualities its aliases name, and distinguish the interval from other intervals and from the ordinal sense of fourth.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Spans four notes","Several qualities","Basic in harmony","Perfect fourth common"],"structure":{"bundles":[{"id":"understand","name":"Understand","description":"What a fourth is.","layers":[{"id":"definition","name":"Definition","description":"Definition.","findings":[{"id":"definition-finding","name":"Definition","description":"Definition.","questions":[{"text":"What is a musical fourth, and how does it differ from other intervals and the ordinal fourth?","kind":"definition"},{"text":"Which quality of fourth is meant?","kind":"boundary"}]}]},{"id":"qualities","name":"Qualities","description":"Qualities.","findings":[{"id":"qualities-finding","name":"Qualities","description":"Qualities.","questions":[{"text":"What are the perfect, augmented and diminished fourth?","kind":"definition"},{"text":"Which entry fits the specific quality?","kind":"action"}]}]}]},{"id":"theory","name":"Theory","description":"Theory.","layers":[{"id":"size","name":"Size","description":"Size.","findings":[{"id":"size-finding","name":"Size","description":"Size.","questions":[{"text":"How many semitones does each quality of fourth span?","kind":"provenance"},{"text":"How is interval size measured?","kind":"measurement"}]}]},{"id":"harmony","name":"Harmony","description":"Harmony.","findings":[{"id":"harmony-finding","name":"Harmony","description":"Harmony.","questions":[{"text":"What role does the fourth play in harmony?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]}]},{"id":"use","name":"Use","description":"Use.","layers":[{"id":"melody","name":"Melody","description":"Melody.","findings":[{"id":"melody-finding","name":"Melody","description":"Melody.","questions":[{"text":"How is the fourth used melodically?","kind":"provenance"},{"text":"Which sources are cited?","kind":"provenance"}]}]},{"id":"tritone","name":"Tritone","description":"Tritone.","findings":[{"id":"tritone-finding","name":"Tritone","description":"Tritone.","questions":[{"text":"Why is the augmented fourth called the tritone?","kind":"provenance"},{"text":"Which sources are cited?","kind":"provenance"}]}]}]},{"id":"context","name":"Context","description":"Context.","layers":[{"id":"intervals","name":"Intervals","description":"Intervals.","findings":[{"id":"intervals-finding","name":"Intervals","description":"Intervals.","questions":[{"text":"How does the fourth fit among musical intervals?","kind":"provenance"},{"text":"Which entry fits interval?","kind":"action"}]}]},{"id":"senses","name":"Senses","description":"Other senses.","findings":[{"id":"senses-finding","name":"Senses","description":"Senses.","questions":[{"text":"How does the interval differ from the ordinal fourth?","kind":"provenance"},{"text":"Is the sense correctly identified?","kind":"boundary"}]}]}]}]},"agentConduct":{"may":["explain the interval","relay its qualities","relay its role in harmony","distinguish it from other intervals"],"mustNot":[],"requiresHuman":[]},"ethics":{"considerations":["The fourth is a basic interval in harmony and melody, and its exact size in semitones depends on its quality, so the quality should be identified.","relay its role in harmony","Basic in harmony"],"affectedParties":[]},"owners":{"steward":"","roles":[],"masterSystems":[]},"relations":[{"target":"musical interval","type":"related","note":"in registry terms"},{"target":"fifth","type":"related"},{"target":"third","type":"related"},{"target":"the ordinal fourth","type":"related"}],"interaction":{"identity":{"applicability":"required","items":[]},"properties":{"applicability":"not-applicable","items":["span: four scale notes note","qualities: perfect, augmented, diminished list","registry parent: interval note"]},"recognition":{"applicability":"optional","items":["An interval spanning four scale steps","Perfect fourth, augmented fourth or tritone","A fifth or third is a different interval; the ordinal fourth is a position in a sequence","Not a visible object; a musical interval, heard between two notes."]},"capabilities":{"applicability":"required","items":["explain the interval","relay its qualities","relay its role in harmony","distinguish it from other intervals"]},"hazards":{"applicability":"required","items":["Confusing the qualities","Confusing with other intervals","Mixing the interval and ordinal senses"]},"interfaces":{"applicability":"required","items":["Music-theory conventions"]},"context":{"applicability":"required","items":["Naming an interval spanning four scale notes.","perfect fourth","augmented fourth","diminished fourth"]}},"sources":[],"openQuestions":["Should the qualities be separate entries?","How should the tritone be handled?","How should the ordinal sense be signposted?","Which entry fits the specific quality?","Which entry fits interval?"],"resources":{"spec":"/models/things/publications/thing-q267984/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q267984/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-14T04:01:24Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"derived","ethics":"derived","owners":"missing","relations":"filled","interaction.identity":"missing","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"missing"},"notes":{"agentConduct":"Affordances listed as what may be done; prohibitions collected from the text.","interaction.properties":"Plane XCT: no invented physical properties.","sources":"Written from model knowledge without web access; claims are unverified."},"score":0.75}}