Rulings

• 2004-10-04
  Disharmony works even if the attacker was not tapped to attack.
• 2004-10-04
  The creature untaps (if it was tapped) before you get control of it.
• 2008-10-01
  The current wording explicitly removes the creature from combat. It is no longer an attacking or blocking creature.
• 2008-10-01
  Disharmony can target a creature you control.
• 2009-10-01
  If you cast Disharmony during an opponent's turn, you may then block with the creature you gain control of (assuming there's an attacking creature it can block).
• 2013-09-20
  If a turn has multiple combat phases, this spell can be cast during any of them as long as it's before the beginning of that phase's Declare Blockers Step.
• 2013-09-20
  If a turn has multiple combat phases, this spell can be cast during any of them as long as it’s before the beginning of that phase’s Declare Blockers Step.
• 2009-10-01
  If you cast Disharmony during an opponent’s turn, you may then block with the creature you gain control of (assuming there’s an attacking creature it can block).