WARNING: There is a bug in the game that could cause you to become stuck and unable to proceed. If you talk to Golo the Goron in the Lanayru Cave after learning the Thunder Dragon's song but before learning the Water Dragon and Fire Dragon's song, your game will not trigger the proper cut scenes to learn the Water Dragon's song and Fire Dragon's song, and you will be stuck. To fix it, you must download a free patch from Nintendo.
After you defeat Bilocyte, Levias tells you about the Song of the Hero. He knows one part of the song, and the three dragons know the other three parts. Levias says to visit the three dragons, then return to him to have him sing the full song.
Because of the aforementioned bug, I recommend learning the Water Dragon's song and Fire Dragon's song before learning the Thunder Dragon's song. Either that or just make sure not to talk to Golo in the Lanayru Cave until you have learned the Song of the Hero.
The Water Dragon
If you go down to the Sealed Grounds statue of Faron Woods, the Imprisoned will be about to break free again.
The Imprisoned, Part 3
Quickly attack its toes as best you can. The Imprisoned walks more quickly than before, so stun it with the Groosenator when you can. Also, remember that if all of the toes are gone from a foot, that foot will no longer send out shockwaves when it stomps.
Once you kill all of the toes, the Imprisoned falls over and you can do upward slashes on the spike to hit it into its head.
After this, the Imprisoned gets a dark halo on its head and slowly floats toward the top of the pit. Shoot it down with the Groosenator and run down to the Imprisoned and hit the spike in again.
After that, the path to Groose's bombs is blocked, so he asks you to run up to the Groosenator. Quickly use the air vents to reach the top. Talk to Groose, who says that he will have to shoot you directly onto the Imprisoned's head. Then get into the Groosenator. Use the control stick to move the Groosenator left or right, and aim at the Imprisoned's head using the Wii Remote. You need to aim right at the spike. Your objective is to land on the Imprisoned's head so you can hit the spike in while standing on the Imprisoned.
If you miss, don't run back up to the Groosenator. Instead, there should be a big air vent coming from the very center of the pit. Run to it and you will be shot all the way into the air and can skydive down onto The Imprisoned's head. Use the sailcloth to avoid getting hurt when you land, then hit the spike into its head with your sword.
If you wait too long to get onto the Imprisoned's head and hit the spike in after the path to Groose's bombs crumbles, you will get a very depressing Game Over.
But if you succeed, go down to the bottom of the pit, hit the spike with a Skyward Strike, then follow the on-screen instructions to slash the sword in the proper directions to seal the spike again.
After dealing with the Imprisoned, when you're back in the sealed grounds temple, the old woman says that the path to Faron Woods has flooded, so you can't go there directly. Groose asks you to go outside to the Groosenator so that he can catapult you to the dragon. Go outside and talk to Groose to be sent to the flooded Faron Woods.
When you land in the water, you can talk to the Kikwi Elder to learn that the water came out of the tree behind him.
Swim into the tree and go to the surface of the water inside. As you go toward the outside exit, the Water Dragon will appear. She wants to test you before teaching you the full song.
Finding the Tadtones
Faron splits her song into pieces and sends little fish-like creatures called Tadtones around the flooded area. You have to collect them all to pass the test. The Tadtones look like small musical notes.
You can use a spin attack to pull nearby Tadtones to you. Some Tadtones are in groups, and if too much time passes before you have completed the group, the Tadtones from that group will swim away and you will have to get them again.
When you swim over to the viewing platform, some monster fish will appear. They turn orange and charge toward you. Just use a spin attack to stun them, then do another spin attack to kill them.
After you have collected a bunch of Tadtones, the Kikwi Elder will call you over, and Fi will give you the ability to dowse for the remaining Tadtones. You will have to swim to the surface and find solid ground to stand on in order to dowse.
To get the Tadtone under the lilypad, swim into the tree and go through the exit at the top near the Water Dragon, then jump down from the tree onto the lilypad to flip it over.
There is also a tadtone in the north part of the map that is trapped behind some rocks. You have to knock the Froak into the rocks to make the Froak explode and break the rocks.
After finding all of the Tadtones, go back to the tree and talk to the Water Dragon. She will teach you her part of the song and restore the woods back to their non-flooded state.
The Fire Dragon
When you go down to Eldin Volcano, the volcano is erupting and you will get blown away on the sailcloth. You will end up with only two hearts, and will wake up in a prison cell of the bokoblins. All of your equipment has been stolen.
Recovering your Stolen Equipment
Walk around your jail cell and a mogma named Plats will appear. He will give you back your mogma mitts.
Dig into the hole in the dungeon room to burrow out to a more open area. Look for the little hut where there aren't any enemies in the way. Sit on the stool for a while to regain all of your hearts.
Go into the tunnel with the torch in it to reach the outside. Save at the bird statue. There is a Gossip Stone nearby that can show you hint movies.
Go to the left to meet Plats again. He will warn you not to let the bad guys see you, and will mark your map with the locations of all of your remaining items.
Climb up the wall behind where Plats appeared. Go a bit to the right where a bokoblin is walking back and forth. Wait for it to walk away, then go along its path and drop down to the left. Be careful of the red chuchu, then burrow into the hole here. Go around and break rocks with your mitts and hit the bombs to reach the other light spot where you can emerge.
Go along the path past the gap in the wall and run up the ledge. You will see a brief cut scene near the lava that shows you that you have to carefully drop down and dig into a burrow hole to avoid the search light, then you can access the gust bellows chest. There is a moldorm in this burrow hole, so be careful. Dig your way up, then go up the ledges to reach the chest that contains the gust bellows.
Use the gust bellows to blow away the nearby chunk of lava, then make your way up to the path. Hide behind the walls to carefully go past the two bokoblins that are walking around. Then dig down into the burrow hole. Get past the moldorm and emerge at the other spot of light.
Drop down and get the clawshots from the chest. Use them on the peahats and then on the vines at the very end.
Drop down, then walk around the ledge to find rocks floating in the lava. You can get into the cave entrance by jumping across the rocks that float past, but the cave only contains healing items and a gossip stone that will appear near the butterflies if you strum the harp.
Go back to the floating rocks and jump onto one, then ride it and jump off at the short ledge to the right with the torch on it. Go up and you will see a cut scene of a bokoblin walking around and a search light. Go up and around, being careful not to let the bokoblin see you, then use the clawshots at the end to get onto the vines. Use a bomb flower to knock down the wooden tower. Then go over and open the chest to get your whip back.
Go to the bridge nearby that has bars on the end. Use the whip to activate the peahat just outside of the bars, then use the clawshot to go to the other side of the bars. Save at the bird statue. There are some bomb flowers on the ramp. Use them to break through the rock walls that block you from reaching the large air vent in the cave to the right of the bird statue. When the path is clear, jump into the large air vent to go up to the area above the long slope.
You will see Plats up ahead. He will say that there are bad guys gathering in the cave up ahead who seem to have found a great treasure. You can't go that way yet, though.
Go over the bridge and use the clawshots to kill the keese. Then go down the slope. There might be a Goddess Cube here if you didn't send it skyward before, but you can't activate it yet because you still don't have your sword. Jump over a floating rock to get into the cave, which just contains healing items and another gossip stone.
Back outside, use the clawshots on the peahats to go toward where the slingshot is. When you're hanging from the last peahat, drop down when a floating rock is under you. Go to the side with the bomb flowers and pick one up when another floating rock comes close. Jump onto the floating rock and throw a bomb flower under the wooden tower, then jump onto the side with the tower when the floating rock reaches the right side of that ledge. With the tower gone, you can go to the blue chest and get the slingshot. Use your clawshot on the peahats to go back up to the last area.
Go up the slope and go through the hut area. You will find some bokoblins walking around. You have to shoot them with the slingshot to stun them, then run past them. Stun the one on top of the wooden tower and burrow into the hole near the base of the tower. Go to the other spot of light and emerge there, then open the chest here to get your bomb bag back. Dig at the dirt here to reveal an air vent, which sends you to a ledge with a bunch of bomb flowers that you can use to restock your bombs if needed. Use a bomb to knock down the wooden tower so you can safely go past.
Use the slingshot to get past the walking bokoblins again. Then go back to the area where you found Plats. In the hot room, use bombs to break the rocks, then go up the ramp and go into the cave.
You will find your sword at the top of a ledge very close by. Pick it up by following the on screen instructions. Go north and you can see some bokoblins guarding a chest.
Go up to the area to the right that Fi mentioned. Kill the cursed spumes with bombs, then ride on the lava chunk. Send the goddess cube skyward, then go up the stairs, but don't go into the hole yet. Instead, go to the ramp and go into the cave area here. Stab a water fruit, then throw it at the lava up ahead to go across. Get past the bokoblins and open the chest to get the rest of your stuff back.
Bomb the rocks at the top of the ledges, then slide down and go to the left, then jump on a floating rock to reach the stairs and go into the cave at the top.
Cut the rope gear with your sword, then use your beetle to cut the two rope gears next to the gate. Go up and the dragon will teach you its part of the song.
The volcano is back to normal, so you can now return to the sky to continue the quest to complete the Song of the Hero.
The Thunder Dragon
The Thunder Dragon is in Lanayru Desert. The dragon is south of Lanayru Caves, so descend to the Ancient Harbor bird statue. Use the clawshot on the pillars on the east side to return to Lanayru Cave.
The goron there is Golo. He is the Goron who can cause a game-breaking glitch if you talk to him after learning the Thunder Dragon's song. Here's how to fix the glitch. It's OK to talk to him before learning the Thunder Dragon's song. Golo will say that he found a passage where he had been digging. If you paid him, you will get paid back ten times what you invested.
Roll a bomb into the rocks in the small passage to get rid of the barrier, then go through.
On the other side, go to the right, bomb the rocks out of the way, and you can read the sign by the door, which says that you can only enter with permission from the thunder dragon.
Go down the slope to the left of the locked door. At the end of the slope, look to the left to see a sparkle on a distant pillar. Use the beetle to retrieve the key. You can't skydive down to it because if you did, there would be no way to get back up again.
Go back to the locked door and go through.
Bringing the Timeshift Stone to the Dragon
Use the clawshot to get to the other side. In this area, thrust with the sword to activate the timeshift stone in the mine cart. Then talk to the robot. Go through the door before the mine cart goes through. Kill any technoblins and babas that get in your way.
In the next area, go over the bridge as it appears and kill the technoblins that appear. Use the clawshot to reach the vines, then step on the switch to open the door to the next area. Hurry through before the cart goes too far away.
Jump onto the bridge and go to the platform with the baba that appears. Kill it, then clawshot over to the vines and step on the switch. Use the clawshot on the vines that appear. Climb to the left, picking up stamina fruit when you can. Leap past the gaps when the air isn't blowing through. At the end, hop down onto the platform that appears. When the mine cart stops, use the clawshots on the targets on the stalactites and then step onto the button.
Use the clawshot targets when they appear on the stalactites to make your way across. At the end, clawshot the vines above the arch. In this passage, a bunch of green chuchus will attack. Kill them all, then kill the babas up ahead and use the whip on the red bar to remove the bars.
Up ahead, get past the technoblin and get out your whip and use it on the bars, but remember not to jump to the other side until it has turned into grass. Otherwise you will sink into the sinksand. Kill the babas that appear from the ceiling, then stand next to the mine cart to avoid the blade traps. Run up the ramp, using the stamina fruit if necessary, and pull the bar.
A bunch of enemies appear in the circular room ahead, including technoblins, sentry robots, and beamos. Kill the beamos that appears in the path of the mine cart. Kill the two beamos next to the door, then step back and target the red bar to pull it down with the whip. Go through.
Cross the bridges that appear. Kill the babas that get in the way. Jump the gaps. When the cart stops, use the beetle to catch a bomb and dump it onto the rocks in the way. Be careful of the quadro baba up ahead. You will then return to the dragon's area. When the mine cart stops, the timeshift crystal will turn the whole region into the past and the dragon will come back to life.
The dragon is too ill to sing, but he mentions that the robots planted a seedling from the tree of life. Its fruit is said to cure any illness.
Go toward the withered tree that you see in the distance. Run across the sand to get up onto the platform with the tree. Blow away the sand pile with the gust bellows, then hit the timeshift stone to make the area go into the past. Send the goddess cube into the sky with a skyward strike while you're here. Dig up the seedling. You will take it with you and can plant it to turn it into the tree of life.
To go back to the dragon's area, use the beetle to hit the mine cart's timeshift stone.
Fly to Faron Woods. You can only go down to the area around the sealed grounds right now. Note that if you do not have the seedling, you will have to fight a boss as soon as you go down to Faron Woods. If you DO have the seedling, then go into the sealed grounds shrine and use the gate of time. Plant the seedling in the area where Groose was (will be) standing when he said that you should plant a seedling. Then go back through the gate of time to find that the seedling has grown into a tree of life with a big fruit on it. Do a roll attack into the tree by holding the A button to run and then shaking the nunchuk before you run into the tree. Collect the fruit.
Go outside and use the bird statue to return to Lanayru Desert. Descend to the Lanayru Gorge statue and give the dragon the fruit. He will sing part of the Song of the Hero.
Learn the Song of the Hero
Now that you know the three dragons' songs, go back to Levias in the Thunderhead and land on Levias's head like you did when you fought Bilocyte. Levias will teach you the song and Fi will make it possible for you to dowse to find the place of the trial. It's on Skyloft, near the Light Tower.