"Parsons code" meaning in English

{
  "etymology_text": "Developed by Denys Parsons for his 1975 book The Directory of Tunes and Musical Themes.",
  "forms": [
    {
      "form": "Parsons codes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Parsons code (plural Parsons codes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Music",
          "orig": "en:Music",
          "parents": [
            "Art",
            "Sound",
            "Culture",
            "Energy",
            "Society",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A simple notation used to identify a piece of music through the falling and rising motion of its pitch."
      ],
      "id": "en-Parsons_code-en-noun-YVH1AZLf",
      "links": [
        [
          "notation",
          "notation"
        ],
        [
          "identify",
          "identify"
        ],
        [
          "music",
          "music"
        ],
        [
          "motion",
          "motion"
        ],
        [
          "pitch",
          "pitch"
        ]
      ],
      "wikipedia": [
        "Parsons code"
      ]
    }
  ],
  "word": "Parsons code"
}

{
  "etymology_text": "Developed by Denys Parsons for his 1975 book The Directory of Tunes and Musical Themes.",
  "forms": [
    {
      "form": "Parsons codes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Parsons code (plural Parsons codes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English eponyms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Music"
      ],
      "glosses": [
        "A simple notation used to identify a piece of music through the falling and rising motion of its pitch."
      ],
      "links": [
        [
          "notation",
          "notation"
        ],
        [
          "identify",
          "identify"
        ],
        [
          "music",
          "music"
        ],
        [
          "motion",
          "motion"
        ],
        [
          "pitch",
          "pitch"
        ]
      ],
      "wikipedia": [
        "Parsons code"
      ]
    }
  ],
  "word": "Parsons code"
}