Tutorials/Redstone music/Doorbell

You need a 2×4×4 area.

You are done!
 * 1) Find where you want your button. It has to be on the bottom block of the wall to the right of the door.
 * 2) Dig down one block below the button.
 * 3) Place redstone dust in the hole.
 * 4) Dig down two blocks on the side of the hole farthest from the door.
 * 5) Place redstone dust in the hole.
 * 6) Dig out a 2×3×3 hole in front of the two existing holes.
 * 7) Place redstone dust on the farthest and nearest blocks to the right.
 * 8) Place a redstone repeater between the redstone dust at four ticks delay.
 * 9) Dig down one block to the left of each piece of redstone dust.
 * 10) Place a block of choice in what you just dug (sets instrument for note blocks).
 * 11) Place a note block on top of each block of choice.
 * 12) Set the tone for the two note blocks.
 * 13) Replace the top layer (ground level) of the hole with a natural block.
 * 14) Place your button.