At Dueling Peaks Stable, the Stable Trotters musical troupe will need to cross the river to perform for Great Fairy Cotera.
Quest Location
Before you can start this quest, you need to complete The Hornist's Dramatic Escape, Honey, Bee Mine, and Serenade to a Great Fairy.
If you have completed those quests, this quest can be started at Dueling Peaks Stable, at 1756, -1956, 0010.
Help the Troupe
After you start the quest, the troupe will go to the river, at 1727, -1999, 0011. Talk to Mastro and he will point out the fallen debris that broke the bridge. Go to the debris and you will find some Zonai devices. Take the Wing (the bird-shaped device) and place it flat on the ground with the wings pointing up. Attach the wagon to the top of the Wing, with the rear axle on top of the tail of the Wing. Next, attach the Controls to the head of the Wing. (Move the wagon farther back if it won't fit.) Attach the Power Source centered on the back of the wagon. Finally, there are two Fans. Attach one to each side of the rear axle.
Place the Wing in the water, then talk to Mastro and say you'll take them across the river. After that, check on the Controls. The Wing will move pretty quickly, and might even start hovering, so you might want to pull back on the controls to slow it down.
Approach the fairy fountain, and there will be a cutscene.
Quest Reward
Mastro gives you 100 rupees as a reward. You can also talk to Great Fairy Cotera from now on to upgrade your armor, and all the Great Fairies can upgrade your armor to a higher level now.