It is a great stall card overall. It's a headache for Nether-Go players. This card is stalling incarnate during the first few turns of the game. Against Control decks it's an amazing pre-emptive counterspell for 1 mana. This card, combined with Memory Lapses and Mana Shorts, is why this deck beats Control decks.
Prison can win most counter wars, because all it's counter spells cost less to play.
Basically, you cast this spell before casting important artifacts such as Static Orb. So the Chant effectively eliminated a counterspell for 1 white mana. Stops Idol as a nice bonus. In the early game, this can almost serve as a time walk. Either way you've disrupted their tempo and slowed them down for a turn, which is generally all you'd like, so you can slam down a Tangle Wire or Static Orb or just Wrath.