You will pick up the side Quest serenade to Kaysa from Mastro at the Outskirt Stable. This quest will set you on the path to freeing the great fairy that is inside the flower pod on the nearby hill, refusing to come out. You will need to track down Pyper, the flute player but he has gone missing. All they know is that he was last seen at the Highland Stables.
When you get to the Highland Stables, walk along the path leaving the stables and you will find Pyper standing in a tree to the right just outside of the main fence. You will hear the flute playing as you get closer.
When you speak to him, he will say that he is having some issues with fire and wants you to help him out with a promise he made. If you do this, he will return to the Outskirt stable and help you with the Serenade to Kaysa quest.
You will pick up a quest called the flue player’s plan. To complete this, you will need to fetch 10 fireflies from the forest to the north. The video guide below will show you how to catch them.
Once Pyper has returned to the stables, you can speak with Mastro again and he will say that they want to go up to the fairy but their cart is broken. You will see a machine nearby with three big wheels attached to a slab and a 4th wheel with a control item nearby. Assemble these to make a 4-wheeled machine with a control stick. Attach Mastro’s cart to this and speak with him when it is done and tell him to get in.
Drive the band up the hill to the fairy and when you get within range a cut scene will start where the band will start playing music that will make the fairy come out of her pod.