{
  "schemaVersion": 3,
  "cityId": "serravane",
  "seed": "serravane-buried-signal-01",
  "title": "The Signal Below the Brine",
  "sourceWorld": {
    "worldId": "serravane",
    "hook": "Build in the living script of a sleeping alien signal organism.",
    "story": "An ivory basin holds a slow impulse beneath mirror-dark brine. Outside, it arrives as isolated glass tones; among the workshops, residents answer it with measured ceramic contacts and a joined pulse."
  },
  "intent": {
    "oneLine": "An uneven five-note whole-tone signal crosses from distant glass and sub-bass into close, dry contacts and restrained civic rhythm.",
    "keywords": ["buried impulse", "brine mirror", "careful graft", "dry ceramic", "listening", "alien but inhabited"],
    "avoid": ["elven harp", "orchestral fantasy", "sweeping choir", "constant shimmer", "busy industrial drums", "literal creature voice"]
  },
  "musicalIdentity": {
    "bpm": 68,
    "swing": 0.08,
    "rootMidi": 34,
    "scale": "whole-tone",
    "signatureMotif": [0, 1, 4, 2, 5],
    "progression": [0, 2, 4, 1],
    "phraseBars": 8
  },
  "worldFingerprint": {
    "meter": "4/4",
    "timingBehavior": "broken",
    "material": "glass-water",
    "spatialShape": "wide-shimmer",
    "arrangementBehavior": "call-response",
    "register": "low",
    "silence": 0.48
  },
  "samplePalette": [
    { "material": "glass", "intensities": ["light"] },
    { "material": "tin", "intensities": ["medium"] },
    { "material": "plate", "intensities": ["heavy"] }
  ],
  "soundEffects": {
    "building.place": {
      "label": "Graft seated",
      "description": "A close tin contact marks a deliberate new connection.",
      "sample": { "material": "tin", "intensity": "medium" },
      "gain": 0.42
    },
    "building.remove": {
      "label": "Clamp released",
      "description": "A lower plate impact marks disconnection from the basin network.",
      "sample": { "material": "plate", "intensity": "heavy" },
      "gain": 0.32
    },
    "placement.invalid": {
      "label": "Signal missed",
      "description": "A quiet glass contact follows the engine's invalid-placement gesture.",
      "sample": { "material": "glass", "intensity": "light" },
      "gain": 0.12
    }
  },
  "spatialMix": {
    "nature": {
      "label": "Open brine pan",
      "description": "Long gaps between glass tones and a low haze leave the buried five-note signal only partly exposed; occasional light contacts suggest mineral edges, not literal water sound.",
      "keywords": ["distant", "unresolved", "slow pulse", "mineral air"],
      "lead": "glass", "bass": "sub", "pad": "haze", "drums": "dust", "texture": "air",
      "brightness": 0.32, "space": 0.85, "grit": 0.08, "density": 0.16
    },
    "city": {
      "label": "Graft and reply",
      "description": "A dry metal beat and round bass answer the same broken motif at a precise work rhythm; organ-like sustained notes are rare and leave room for the black filament's silence.",
      "keywords": ["repair", "contact", "collective listening", "measured"],
      "lead": "pulse", "bass": "round", "pad": "organ", "drums": "metal", "texture": "machinery",
      "brightness": 0.42, "space": 0.28, "grit": 0.33, "density": 0.40
    },
    "transition": {
      "curve": "equal-power",
      "description": "Both sides keep the same eight-bar roots and broken five-note call; moving inward makes the civic reply and close contacts audible while the distant glass recedes."
    }
  }
}