In The Legend of Zelda: Tears of the Kingdom, you can obtain the Serenade to a Great Fairy side adventure from Penn at the Woodland Stable after starting the Potential Princess Sightings side adventure.
For this side adventure, use Ultrahand to grab some wheels from around the stable then place them on the breezer. You’ll then need the Towing Harness, which you can get as a reward from the Pony Points. You’ll also need a horse.
After you’ve attached the horse to the breezer using Ultrahands, hop on the mount and steer it to the Great Fairy who can be found to the north. Just follow the road to the giant plant spewing purple dust.
Once you arrive, the musician will play her violin and the Great Fairy will reveal herself.