         changeset = Performance.changeset(%Performance{}, params, round)
         refute changeset.valid?
 
-        assert changeset.errors[:base] ==
+        assert changeset.errors[:appearances] ==
                  {"The performance must have at least one participant.", []}
       end
 

        params = Map.put(valid_attrs, :pieces, [])
        changeset = Performance.changeset(%Performance{}, params, round)
        refute changeset.valid?
        assert changeset.errors[:base] == {"The performance must have at least one piece.", []}
      end
    end



        changeset = Performance.changeset(%Performance{}, params, round)
        refute changeset.valid?

        assert changeset.errors[:appearances] ==
                 {"The performance can't have only one ensemblist.", []}
      end

      @tag round: round
