Entrancing Melody

Oracle Text

Gain control of target creature with converted mana cost X.

Card Rulings

9/29/2017 If a permanent has in its mana cost, X is considered to be 0.
9/29/2017 The control-change effect of Entrancing Melody lasts indefinitely. It doesn’t wear off during the cleanup step.
9/29/2017 In a multiplayer game, if a player leaves the game, all cards that player owns leave as well, and any effects that give the player control of permanents immediately end.