Step 1: Get your stuff together!
And you'll also need a music .mp3 file to make scary.
Step 2: Import your audio file
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
Step 4: Make the audio scary
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.