Instructions
Head northwest through Hyrule Field until you reach Zora's River. Make your way through this short puzzle until you reach the giant waterfall. Stand on the stone square directly in front of the waterfall and play Zelda's Lullaby on your ocarina in order to open the way to Zora's Domain.
Enter Zora's Domain and follow the stone path, taking the left trail when the path forks. This will lead you up a set of stairs and ultimately into King Zora's throne room.
Step onto the pedestal and press the "A" button to talk to King Zora.