curl --request POST \
  --url https://api.iotools.cloud/v1/tool/musical-interval-converter \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "inputType": "semitones",
  "value": "7",
  "precision": "4",
  "baseFreq": "440",
  "detuneCents": "0"
}
'

{
  "tool": "musical-interval-converter",
  "tool_version": "1.0.1",
  "outputs": {
    "semitones": "7",
    "cents": "700",
    "ratio": "1.4983",
    "intervalName": "Perfect 5th (P5)",
    "resultFreq": "440",
    "tuningTable": [
      {
        "system": "Equal Temperament — Perfect 5th (P5)",
        "cents": "700",
        "ratio": "1.4983"
      },
      {
        "system": "Just Intonation — Perfect 5th (P5)",
        "cents": "701.955",
        "ratio": "3/2 (1.5)"
      },
      {
        "system": "Difference (JI − ET)",
        "cents": "+1.955 ¢",
        "ratio": "1.0011"
      }
    ],
    "referenceChart": [
      {
        "semitones": "0",
        "cents": "0",
        "ratio-et": "1",
        "interval": "Perfect Unison (P1)"
      },
      {
        "semitones": "1",
        "cents": "100",
        "ratio-et": "1.0595",
        "interval": "Minor 2nd (m2)"
      },
      {
        "semitones": "2",
        "cents": "200",
        "ratio-et": "1.1225",
        "interval": "Major 2nd (M2)"
      },
      {
        "semitones": "3",
        "cents": "300",
        "ratio-et": "1.1892",
        "interval": "Minor 3rd (m3)"
      },
      {
        "semitones": "4",
        "cents": "400",
        "ratio-et": "1.2599",
        "interval": "Major 3rd (M3)"
      },
      {
        "semitones": "5",
        "cents": "500",
        "ratio-et": "1.3348",
        "interval": "Perfect 4th (P4)"
      },
      {
        "semitones": "6",
        "cents": "600",
        "ratio-et": "1.4142",
        "interval": "Tritone (TT)"
      },
      {
        "semitones": "7",
        "cents": "700",
        "ratio-et": "1.4983",
        "interval": "Perfect 5th (P5)"
      },
      {
        "semitones": "8",
        "cents": "800",
        "ratio-et": "1.5874",
        "interval": "Minor 6th (m6)"
      },
      {
        "semitones": "9",
        "cents": "900",
        "ratio-et": "1.6818",
        "interval": "Major 6th (M6)"
      },
      {
        "semitones": "10",
        "cents": "1000",
        "ratio-et": "1.7818",
        "interval": "Minor 7th (m7)"
      },
      {
        "semitones": "11",
        "cents": "1100",
        "ratio-et": "1.8877",
        "interval": "Major 7th (M7)"
      },
      {
        "semitones": "12",
        "cents": "1200",
        "ratio-et": "2",
        "interval": "Perfect Octave (P8)"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}