Walkthrough:The Legend of Zelda: Majora's Mask/Xykeb Zraliv/Pieces of Heart 27-52

Piece of Heart #27
Go to Zora Hall and go into Mikau's room. Hookshot onto the second floor and read Mikau's diary in Zora form to learn some tunes you have to memorize. Go to Japas' room and play what you learned. Afterward, go to Evan's room and take off the Zora Mask. Play the entire song (Japas' parts too) for a Piece of Heart.
 * Items required: Zora Mask, Ocarina of Time, Hookshot

Piece of Heart #28
Go to the Oceanside Spider House. Go downstairs and to the dining room (the first door you encounter). Shoot the masks on the far wall in this order: yellow, green, red, blue, green, blue. Go into the room that opens up and open a chest for a Piece of Heart.
 * Items required: Hero's Bow

Piece of Heart #29
Defeat Gyorg. Afterward, go to the first Great Bay area (with the Marine Biology Lab, the entrance to Pinnacle Rock, etc.) and go to roughly the middle of the screen. You should find a boat near some land. Jump on it and it will start moving. As it passes some islands with trees, Hookshot to them. Talk to the fisherman to play a minigame. The minigame is simple; just jump to the island where the torch is lit. After winning, you will receive a Piece of Heart.
 * Items required: Hookshot

Piece of Heart #30
Defeat Goht. Go to the Laundry Pool and talk to the frog with the Don Gero's Mask. Go to Southern Swamp and hop along lilypads until you reach a platform with a frog on it. Talk to it with the Don Gero's Mask. Go to Woodfall Temple and fight the Gekko. Talk to the frog that appears with the Don Gero's Mask. Go to Great Bay Temple and fight the Gekko. Talk to the frog that appears with the Don Gero's Mask. Then go to the area of Mountain Village with the smiths and go to the lake with frogs on it. Talk to them with the Don Gero's Mask for a Piece of Heart.
 * Items required: Don Gero's Mask, Deku Mask, Hero's Bow, Ice Arrows

Piece of Heart #31
Go to Ikana Graveyard at the second night. Talk to the Stalchildren circling a grave and tell them to open it. Use the Lens of Truth and walk through a wall. Go through this next room using the Lens of Truth, and at the end, turn left and bomb the wall. Kill the Iron Knuckle for a Piece of Heart.
 * Items required: Captain's Hat, Lens of Truth, Bomb Mask or Bombs

Piece of Heart #32
Go to Ikana Canyon. Find the Spirit House (the place with the Poe Salesman and the Poe Sisters) and fight the Poe Sisters. If you do it within the time limit, you will receive a Piece of Heart.
 * Items required: None

Piece of Heart #33
Go to Southern Swamp and give the Deku here the Town Title Deed (you must be in Hylian form). Fly onto the nearby building for a Piece of Heart.
 * Items required: Deku Mask, Town Title Deed

Piece of Heart #34
Go to Mountain Village and visit the Deku near the area with the Lens of Truth. Give him the Swamp Title Deed (you must be in Deku form). Fly onto a nearby cliff for a Piece of Heart.
 * Items required: Deku Mask, Swamp Title Deed

Piece of Heart #35
Go to Zora Hall and go into Lulu's room. Give the Deku here the Mountain Title Deed (you must be in Goron form). Fly onto a nearby cliff for a Piece of Heart.
 * Items required: Deku Mask, Mountain Tile Deed, Goron Mask

Piece of Heart #36
Go to Ikana Canyon and go to the area near Sakon's Hideout. Give the Deku here the Ocean Title Deed (you must be in Zora form). Fly to a nearby cliff for a Piece of Heart.
 * Items required: Deku Mask, Mountain Title Deed, Zora Mask

Piece of Heart #37
Go to Ancient Castle of Ikana. Go inside and take the left path until you reach the roof. Climb onto the edge of the castle, then shoot a crystal switch to the south. Jump to a pillar with a Deku Flower, then fly east to a Piece of Heart.
 * Items required: Deku Mask, some sort of projectile

Piece of Heart #38
Go to Ikana Canyon, then go upriver to a cave behing the waterfall. Shoot the sun switch, then fight the minibosses in here. Open the chest that appears for a Piece of Heart.
 * Items required: Light Arrows, at least 16 Heart Containers

Piece of Heart #39
Go to the bathroom in the Stock Pot Inn at night. A hand will be sticking out of the toilet. Give him a paper item and he will give you a Piece of Heart.
 * Items required: Some sort of paper object (any Title Deed, Letter to Kafei, or Letter to Mama)

Piece of Heart #40
Go to Romani Ranch and go to the Doggy Racetrack. Talk to Mamamu Yan, bet 80 rupees, take a dog (if you're using the Mask of Truth, wait until you find one that says something encouraging), and bring it to her. If your dog places first or second, you will get a Piece of Heart.
 * Items required: None, although the Mask of Truth makes it less about pure dumb luck

Piece of Heart #41
Go to the Stock Pot Inn and go to Anju's Grandmother's room. Put the All-Night Mask on and ask her to tell you the first story. When she's done, answer her question correctly for a Piece of Heart.
 * Items required: All-Night Mask

Piece of Heart #42
Go to the Post Office from 2:00 p.m. until evening. Wear the Bunny Hood if you have it and talk to the Postman. You will play a minigame where you have to press A at exactly 10 seconds. The Bunny Hood lets you see the timer. When you do this, you will get a Piece of Heart.
 * Items required: None, but the Bunny Hood makes it easier

Piece of Heart #43
Go to the Stock Pot Inn and go to Anju's Grandmother's room. Put the All-Night Mask on and ask her to tell you the second story. When she's done, say "I dunno" for a Piece of Heart.
 * Items required: All-Night Mask

Piece of Heart #44
Go to East Clock Town and play Honey & Darling's minigame every day (it changes every day) and get a perfect score each day for a Piece of Heart.
 * Items required: Hero's Bow, Bomb Bag

Piece of Heart #45
Go to North Clock Town and slash the grass. Answer the Keaton's questions for a Piece of Heart.
 * Items required: Keaton Mask

Piece of Heart #46
Go to Mayor Dotour's office and talk to him wearing the Couple's Mask for a Piece of Heart.
 * Items required: Couple's Mask

Piece of Heart #47
Deposit 5000 rupees to the bank. This must be done gradually over the course of the game.
 * Items required: 5000 rupees

Piece of Heart #48
Wearing the Postman's Hat, go to any postbox in Clock Town. It will give you a Piece of Heart.
 * Items required: Postman's Hat

Piece of Heart #49
Go to the Odolwa Dungeon inside the moon. Fly to a ledge with a Piece of Heart.
 * Items required: Deku Mask

Piece of Heart #50
Go to the Goht Dungeon inside the moon. Using the Goron Mask, roll you way through. Don't move the control stick until you clear the magic pots. Then go around a bend, over a ramp, around another bend, around another bend, over a ramp, around another bend, then try to straighten yourself, as you'll be on a narrow straight path. Don't move the control stick and you'll end up near a Piece of Heart.
 * Items required: Goron Mask, incredible patience, at least an hour of free time

Piece of Heart #51
Go to the Gyorg Dungeon inside the moon. In Zora form, swim through the tunnels going left, right, left, left. Behind the Gossip Stone is a Piece of Heart.
 * Items required: Zora Mask

Piece of Heart #52
Go to the Twinmold Dungeon inside the moon. Make your way through it. Eventually, you'll find the Piece of Heart sitting there in plain sight.
 * Items required: None