Prize Wall

Spending rather than tapping the permanent doesn’t let you activate abilities of creatures that have “summoning sickness.” That is, if a creature’s ability has in the cost, and it hasn’t been under your control since the beginning of your most recent turn, you can’t activate the ability (unless the creature has haste), even if you intend to spend rather than tap the creature.
Spending allows you to activate the tap ability of a creature that’s already tapped. Normally, you couldn’t pay the cost of tapping the creature because it’s already tapped. With Sole Performer, you don’t have to worry about that. You have !
You lose unused as steps and phases end, at the same time you lose unspent mana.
Although acts in many ways like mana, it is not mana. An ability that triggers from a creature tapping to add mana wouldn’t trigger when you activate Sole Performer’s ability, for example.
You can’t spend to have a creature attack without tapping. You also can’t use it to pay the cost of an ability that taps a creature without using the symbol. For example, you can’t activate an ability that says “Tap an untapped creature you control: [Do something]” with .