Go to the broken bridge in front of you, freeze both enemies with ice arrows to cross it, then throw your Hookshot at branches to climb the cliff. Upon reaching the top, activate the Owl Statue.
Note: With the statue activated, you should be ready to solve the Anju and Kafei quest which stretches over three days. This side quest can be done later, but before getting on the moon if you want the last mask.
Climb the slopes and make Tingle fall to buy the map of Stone Tower for 20 rupees. Go to the far north and get in the Spring Water Cave. Walk a little bit and you see Sharp, Flat's brother. Play the Song of Storms for him, which makes the water flow and the Music Box's watermill work. Sharp thanks you and asks you to go to the temple. You should seek out for the king who knows how to get there. Leave this cave and go towards the Music Box House.
A small girl is opening the door and closing it right after. Put on your Stone Mask to turn invisible and get in the next time she is getting out, or use a bomb to make her go out right away. If you don't have the Stone Mask, wait for her to get out, and once she is far enough, rush in the Music Box House. Climb down the stairs and get close to the cupboard. When the poor man gets out, play the Song of Healing (do not go near him) to free him from his curse and pick up the Gibdo's Mask. Leave the house.
Beneath The Well
Before getting in the Ikana Well you will need: a bottle of Milk (buy it 50 rupees from the Gorman Brothers near the ranch or 20 rupees from the Milk Bar if you got Romani's Mask), an empty bottle, 5 Magic Beans (buy them from the Swamp Business scrub), 10 nuts, 10 bombs and one fish (in the Inn's kitchen for example). (You can find some of these things within the well but you would need additional items like a Red Potion...)
3DS: You need the same items, but only one copy is enough!
When you're ready, climb all the slopes to the west, then climb down the ladder into the well. Beneath the well you have to be always moving, if not you will hear a blow and a hand will fall from the ceiling to take you back to the entrance.
Put on the Gibdo's Mask and talk to the Gibdo in front of the door on the right. Give him a Magic Bean and open the door. Go ahead, then give one nut to the Gibdo and open the door. Move on, go left and talk to another Gibdo. Give him a bomb and get in. Go to the middle of the room, shoot five arrows at the ghost (when it's not spinning around) and pick up its soul in an empty bottle. Go back to the room where you gave the nut, talk to another Gibdo and give him the fish. Go straight ahead and give the Big Poe to the next Gibdo. Open the door, watch out for the spikes and talk to the Gibdo. Give him the milk bottle and get in the last room. Light all four torches with fire arrows, open the newly-appeared chest and pick up the Mirror Shield. Use this shield to get the light from the ceiling and reflect it on the sun drawing, which makes a ladder appear. Next, do the same with the block, which reveals a passage. Follow this passage to get out of the well, then climb the ladder.