src/main/resources/builtin/loot/entities/creeper.json

{
  "items": [
    {
      "default": {
        "count": 0,
        "item": "net.glowstone.util.loot.LootingUtil.randomMusic()"
      },
      "conditions": [
        {
          "condition": "ENTITY_KILLER_SKELETON",
          "count": 1
        }
      ]
    },
    {
      "default": {
        "count": {
          "max": 2
        },
        "item": "sulphur"
      }
    }
  ],
  "experience": {
    "count": 5
  }
}