In the area between Mountain Village and Goron Village (with all the bridges and white wolfos, etc.) go down to the lower area, where the floor is made of ice. Inside one of the giant snowballs is the Goron Elder, but he's frozen. Use a bottle of hot spring water (there's a bottle in Darmani's tomb, just pull the grave back) to melt the ice and free him. This will take a couple of tries since you only have so much time before hot spring water cools off to become regular spring water. He'll teach you the first 6 notes of Goron's Lullaby. Go to Goron Village and pund the ground in front of the dome's door to open it. Play the first six notes of the lullaby and the Elder's son will teach you the rest.
