Green Isn't Just For Envy

Harry's failing Potions - what's new. Snape is being his usual poisonous self and Harry doesn't stand a chance. However, when the class is informed there will be a practical Potions exam in a few days, Sirius has an idea that could turn things around for the Chosen One. Add in Malfoy, jealousy, an ancient heirloom, and some musical talent, and who knows what might happen. Drarry.