{"id": "card_music_intervals", "kind": "reference", "title": "Intervals — the harmonic series in small ratios", "body": "The octave is the ratio 2:1, the perfect fifth 3:2, the fourth 4:3 — the consonant intervals are the low harmonics of a vibrating string or air column, sealed on the music-theory stick. A chord is stacked ratios.", "source": {"label": "Narrow Highway — music", "url": "", "authority_tier": "engine_derived"}, "shelf": "codex", "box": "music", "bands": ["music", "pillar", "intervals", "one map"], "subject": "Intervals — the harmonic series in small ratios", "connections": [{"to_card_id": "card_floor_music", "relationship": "part_of", "evidence": "a pillar (Intervals)"}, {"to_card_id": "card_floor_acoustics", "relationship": "connects_at", "evidence": "intervals are ratios of the harmonic series - the physics of sound"}], "author": "engine", "created_at": 0.0, "updated_at": 0.0, "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "generated": false, "call": "codex.music", "facets": {"subject": ["intervals", "one map", "pillar"]}, "presentation": {"glyph": "•", "kind_label": "music", "by": "Narrow Highway — music", "authority": "engine_derived", "posted": "", "standing": ""}, "neighbors": [{"id": "card_floor_music", "title": "Music — interval, tuning, and the harmonic series", "relationship": "part of", "why": "a pillar (Intervals)", "href": "/card/card_floor_music", "resolved": true}, {"id": "card_floor_acoustics", "title": "Acoustics — waves, loudness, and harmonics", "relationship": "connects at", "why": "intervals are ratios of the harmonic series - the physics of sound", "href": "/card/card_floor_acoustics", "resolved": true}], "house": {"door": "FIND", "kind": "card", "trail": "connections", "seal": "/card/card_music_intervals", "next_step": {"do": "follow a connection: what this card rests on, and what rests on it", "door": "FIND", "tool": "card_connections", "params": {"id": "card_music_intervals"}}, "ends": "a verdict or a card · the trail · a seal · one next step"}}