This is my first Instructable and it shows how to make any music (mp3) file sound scary using the free software tool, Audacity. An example of scary music is this video: http://youtube.com/watch?v=Jwj0gLriTnk
Step 1: Get your stuff together!
If you don't already have it you need to download and install Audacity and the LAME MP3 encoder from this link: http://audacity.sourceforge.net/download/windows
And you'll also need a music .mp3 file to make scary.
Step 2: Import your audio file
After opening audacity go to the toolbar at the top and click the following: Project-->Import Audio... Find your music file and import it. If your using Audacity for the first time you'll probably have to find the lame_enc.dll file first so follow the steps provided on screen if prompted.
After importing your file you should get something in the little gray area looking like this. This is called an audio track.
Step 3: Duplicate your audio track
First your going to need 3 copies of that audio track in order for this to work. Click on your audio track and go to the toolbar again and this time do Edit-->Duplicate twice so you end up with 3 tracks that are exactly the same.
Step 4: Make the audio scary
Now that you have 3 separate audio tracks click on the first one so that only it has the bluish tint on it (This means its selected). Then go to the toolbar and go Effect-->Change Pitch...
It should bring up a little menu and in the middle of the menu there's something that says "Semitones (half-steps):" with a box next to it. Enter the number 2 into that field then press OK.
Now select the middle audio track and go Effect-->Change Pitch... This time your going to enter the number
-2 into the semitone field and press OK.
Finally select the last audio track and go Effect-->Change Pitch... and enter the number -4 into the semitone field, press OK.
Then click play and wallah! Ghostly music.
For a slightly different effect you can use 3,-3,-6 for the semitones. Depending on the kind of music your using try different combonations. But to get the ghastly sound effect A,B,C A=Variable, B=-A, C=-2A.