Where are all the secret music disk located?
Here are the locations of all of the music discs hidden throughout the tutorial world in Minecraft for Xbox, according to the Minecraft Wiki:
Where Are We Now? - (X: 373 Y: 65 Z: -146) On an island On the east border of the map. [Also contains Pickaxe].
Strad - (X: 28 Y: 61 Z: 9) Is in a cave underground with pillars up on top . [Also contains Iron Axe with Fortune III].
Cat - (X: -42 Y: 57 Z: 249) In the swamp cabin to the left of the mansion. [Also contains Iron Boots with Feather Falling IV].
11 - (X: 63 Y: 93 Z: 166) On top of the glass of the mansion. [Also contains Bow with Power V].
13 - (X: 107 Y: 75 Z: 165) In the tunnel exiting the tutorial area. [Also contains Jukebox, Bow with Flame I, and 20 Arrows].
Ward - (X: 197 Y: 78 Z: 71) Behind tutorial area, on top of the tower. [Also contains Iron Pickaxe with Unbreaking III].
Chirp - (X: 42 Y: 77 Z: 153) Behind the lava-fall in the mansion brewing room. [Also contains Iron Chestplate with Fire Protection V].
Mellohi - (X: 86 Y: 75 Z: 166)under the cobblestone cross in the middle of the stone slabs[also contains iron sword with smite v]
Mall - (X: 102 Y: 60 Z: 268) To the left of the mansion, take the minecart to the sand temple. [Stepping on the pressure plate gives Iron Sword with Looting III from a dispenser].
Blocks - (X: 65 Y: 71 Z: 176) Basement of the mansion . [Also contains Iron Helmet with Respiration III].
Far - (X: -41 Y: 59 Z: 93) In the glass building under the water. [Also contains Iron Shovel with Efficiency V].
Stal - (X: 60 Y: 61 Z: 27) This disc is the only one located in the Nether. It can be found in a humongous Nether Fortress. next to a blaze spawner [Also contains Flint and Steel and enchanted Iron Leggings].
According to the Minecraft Wiki:
The music discs "13" and "cat" are found in 8% of dungeon chests. All music discs can be obtained by getting a creeper to be killed by a skeleton's arrow.
To find the discs either go raiding dungeons or get a skeleton to shoot a creeper. To do that go up to a skeleton and wait for him to acquire you (start attacking) then find a creeper and try to get the skeleton to shoot it.