Both can be used by paying their normal ink cost, but songs have the added benefit of being able to be played for free if you have the right character - worth at least the value of the song - already on the field
With a modest two strength and three willpower, helping to bolster your inkwell is the reason to have Winnie the Pooh, Having a Think in your deck
More broadly, youd want to prioritize cards that make white spells cheaper like The Wind Crystal and Pearl Medallion and obviously other cards that offer mechanical interactions with legendaries like Gandalf the White and Heroes Podium
If this all sounds confusing, thats because it is
Luckily, you'll often only be casting spells on your turn to begin with (minus interaction like counterspells)
Not only that, this card has a good amount of willpower and lore-generating capability too, since each quest gets you three lore, so it can tank some damage and still help you win the game.