This elegant loop relies on Enchanted Evening to fundamentally rewrite the battlefield, turning every permanent—including lands—into an enchantment alongside its other types. That transformation is the key that unlocks Composer of Spring, allowing any entering land to trigger the Composer's constellation ability. When you play Selesnya Sanctuary, it enters as an enchantment and triggers both its own bounce clause and the Composer of Spring. You use the bounce to return Selesnya Sanctuary to your hand, and the Composer's trigger to drop it right back onto the battlefield, creating a self-sustaining loop that generates infinite landfall triggers.