Tutorials/Programs and editors/Minecraft Note Block Studio

Minecraft Song Planner is an application made for Note Block musicians, currently at version 2.0. It allows you to compose songs by placing note blocks on the workspace and change their instruments and pitch. The amount of resources required is displayed, as well as the length of the song.

To download it, visit the official Minecraft Forums topic.

History
It is created by David "Davve" Norgren and was first released on January 20th 2011 as version 1.0. After 2 months and 11,000 downloads, version 2.0 was released on March 20th. It features a better interface, an infinite amount of layers and Select mode, allowing copying/cutting/pasting/deleting of any number of Note blocks at once.

Use
Left-click anywhere on the workspace to place a note block. Its pitch will depend on the selected piano key and its instrument will be the selected instrument. You can delete note blocks by holding down the right mouse button. If you delete something by accident, you can undo it.

When in select mode, click and hold down the left mouse button to select the wished note blocks. Click and drag on any selected note block to move the selection around. Release the left mouse button to place the selection down (Note that this will overwrite any underlying blocks).

Building the songs in Minecraft
Once you have created a song in the program, you can build it in Minecraft using different circuits. You are recommended to use redstone repeaters for this (A video showing how to build such circuits can be found here).

The number of right-clicks required to reach the pitch for each note block is displayed in white text. The instrument can be recognized by the color scheme the program uses. You can go to Settings>Show material icons on note blocks if you find it easier to see material icons of the instruments (The Harp blocks doesn't require any material).