"backdoor progression" meaning in All languages combined

{
  "forms": [
    {
      "form": "backdoor progressions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "backdoor progression (plural backdoor progressions)",
      "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"
        }
      ],
      "examples": [
        {
          "text": "A backdoor progression in C (Fm⁷→B♭⁷→C):\n{1}",
          "type": "example"
        }
      ],
      "glosses": [
        "A chord progression of iv⁷ to ♭VII⁷ to I, common in jazz."
      ],
      "id": "en-backdoor_progression-en-noun-urTT~ugM",
      "links": [
        [
          "chord progression",
          "chord progression"
        ],
        [
          "jazz",
          "jazz"
        ]
      ]
    }
  ],
  "word": "backdoor progression"
}

{
  "forms": [
    {
      "form": "backdoor progressions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "backdoor progression (plural backdoor progressions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with usage examples",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Music"
      ],
      "examples": [
        {
          "text": "A backdoor progression in C (Fm⁷→B♭⁷→C):\n{1}",
          "type": "example"
        }
      ],
      "glosses": [
        "A chord progression of iv⁷ to ♭VII⁷ to I, common in jazz."
      ],
      "links": [
        [
          "chord progression",
          "chord progression"
        ],
        [
          "jazz",
          "jazz"
        ]
      ]
    }
  ],
  "word": "backdoor progression"
}