The Legend of Zelda Glitches

Self Unlocking Door
1) In the normal quest make your way to Eagle dungeon (the first one, in a tree), you must not have been into the dungeon before.

2) Enter the dungeon, notice that right in front of you is a locked door.

3) Exit the Dungeon.

4) Enter the dungeon.

The door will now be unlocked! Convenience!

Solid Walls?
1) In the second quest find any dungeon wall that you can walk through in both the north and south directions. (In Level 2, the wall that borders the north side of the whistle room will suffice.)

2) Start on the north side of the wall. Walk south through it, then immediately turn north and go through it again.

3) When Link finishes going through it, part of him will still be in the wall. Push south and he'll enter the wall as if it were an open doorway.

4) Walk through it.

Link will come out the other side and move a full tile away from the wall, even if there are stones in the way! (You can walk off the stones to the south in most cases.)

Indoor Music
1) Purchase the Blue Ring.

2) Exit and re-enter the store while your Rubie counter is still counting down.

About 50% of the time, when you re-enter, the overworld music will continue to play while inside.

There are other ways to get the glitch to work as well. The only requirement is that your Rubie counter is changing as you enter a cave/stairway from outside. This can be done after finding a 100-Rubie secret, after being slapped with a Door Repair fee, or after winning/losing big at the Money-Making Game. I also emember once getting this to happen after an enemy dropped 5 Rubies right on a stairway. Note that in the above instructions, you don't have to re-enter the same place you exited, provided you can get to another place before the Rubie counter finishes the transaction.

Portable Fairy
This can only be done in the second quest. Note how the whistle always warps you to the entrances of Quest 1 dungeons, even during the second quest (so after beating level six, the whistle takes you to where you found level six in the first quest, not the second.) Also note that level five's former location becomes a fairy fountain in the second quest.

1) Warp to the fairy fountain that used to be at level five. (You must have completed the first four levels to do this - you do NOT, however, need to have completed level five, as the game reverses those two dungeons internally.)

When you arrive, the fairy will heal you, but you can continue to move while still receiving health. This lets you go anywhere else in the game (even into a dungeon) while your hearts continue to fill up. It is a sort of invincibility since any damage you take in the meantime will be automatically recovered.

By the way, the whistle's warp destination can be controlled. If you know where you warped last, you can warp to the next completed dungeon in sequence by blowing the whistle while facing north or east. If you blow the whistle while facing west or south, you will be taken to the previous warp destination in sequence. Also, if you blow the whistly multiple times while the whirlwing approaches, you can cycle through the sequence as much as you want in either direction. Remember that the whistle only takes you places where you completed the dungeon, so if you do them out of order, you should skip over the unfinished dungeons in your count.