Anime Instrumentality: "Whether they set the mood, deliver sentiments not carried across in dialogue, or accentuate certain themes within a show, anime songs work to add value to a show.
What may get overlooked, however, is that the reverse also applies: anime also add value to their respective OP and ED themes. And I’m not talking commercial value. (That may be topic for another day.) The element that arguably propels a merely enjoyable anisong into something great comes from how intimately the song is tied to the anime.
Spoilers to follow for Natsume Yuujinchou, Steins;Gate, and Puella Magi Madoka Magica."