Song Magic Rules

Musical spells are a peculiar type of magic that allow a person to imbue their notes with magical power that enhances the power of music beyond what it would normally be capable of. These songs often work on the heart and then the mind, with little impact on the physical world, and they usually affect everyone the same whether friend or foe. The one exception is the person playing a magical song, who can choose whether they are under the effects of their own music or not. 
The biggest quirk of magical songs is the act of playing. If you cast a magical song, you may continue the effect on future turns by continuing to play it, provided the spell states you can do that. This requires no more Spirit expenditure and keeps the effect going, but it takes both your action and your concentration. You reroll the spell to see if it still goes. The effect of a song cannot last more than one hour.