"can't carry a tune in a bucket" meaning in English

{
  "forms": [
    {
      "form": "can't carry a tune in a bucket",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "couldn't carry a tune in a bucket",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "can't<can't,-,couldn't,-> carry a tune in a bucket"
      },
      "expansion": "can't carry a tune in a bucket (third-person singular simple present can't carry a tune in a bucket, no present participle, simple past couldn't carry a tune in a bucket, no past participle)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English negative polarity items",
          "parents": [
            "Negative polarity items",
            "Terms by semantic function"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "To sing very badly."
      ],
      "id": "en-can't_carry_a_tune_in_a_bucket-en-verb-q9IHn0vA",
      "links": [
        [
          "sing",
          "sing"
        ],
        [
          "badly",
          "badly"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, slang) To sing very badly."
      ],
      "related": [
        {
          "word": "carry a tune"
        },
        {
          "word": "couldn't carry a note in a bucket"
        },
        {
          "word": "tin ear"
        }
      ],
      "tags": [
        "idiomatic",
        "no-past-participle",
        "no-present-participle",
        "slang"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "Translations",
          "word": "laulaa kuin varis"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "Translations",
          "word": "chanter comme une casserole"
        }
      ]
    }
  ],
  "word": "can't carry a tune in a bucket"
}

{
  "forms": [
    {
      "form": "can't carry a tune in a bucket",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "couldn't carry a tune in a bucket",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "can't<can't,-,couldn't,-> carry a tune in a bucket"
      },
      "expansion": "can't carry a tune in a bucket (third-person singular simple present can't carry a tune in a bucket, no present participle, simple past couldn't carry a tune in a bucket, no past participle)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "related": [
    {
      "word": "carry a tune"
    },
    {
      "word": "couldn't carry a note in a bucket"
    },
    {
      "word": "tin ear"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English negative polarity items",
        "English slang",
        "English terms with non-redundant non-automated sortkeys",
        "English verbs",
        "Translation table header lacks gloss"
      ],
      "glosses": [
        "To sing very badly."
      ],
      "links": [
        [
          "sing",
          "sing"
        ],
        [
          "badly",
          "badly"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, slang) To sing very badly."
      ],
      "tags": [
        "idiomatic",
        "no-past-participle",
        "no-present-participle",
        "slang"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "Translations",
      "word": "laulaa kuin varis"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "Translations",
      "word": "chanter comme une casserole"
    }
  ],
  "word": "can't carry a tune in a bucket"
}