Instructions
Open up "GarageBand" on your computer and choose "New Project" from the initial menu that opens up.
Name your song something you will remember later on and select the "Create" command. Select "Record" to record your first song. Hit the "Record" button again when you have finished the song. This same process should be completed multiple times for multiple songs that you wish to use to create your collage. You can create multiple song recordings, one right after the other, without having to do anything but open up a new window to record the next song.
Open the editor function within "GarageBand" to change the pitch or other features of the music as you wish. You can add and subtract notes, change the tempo and cut and splice your music as you wish. Cutting and pasting the various tracks you have recorded will allow you create your collage.
Select the track that you wish to edit in the editor by highlighting it. Move the marker on the ruler at the top of the screen to the right until you have selected the portion of music that you want to copy. Wherever the marker ends on you music timeline is where it will cut off.
Select the "Edit" option from the menu at the top of your screen and scroll down to the "Cut" option. Doing this will cut the track from the current song.
Open up a new window to create another song. Click the "Edit" option again and select paste. Doing this will place the track in the new collage you are making. Repeat the process by cutting and pasting the track from the other songs you have recorded.
Arrange the music in your new musical score by dragging each track to the place where you want it to play.
Join each music section to the others by selecting "Edit" and then "Join" from the menu at the top of the screen.
Play around with the looping and other effects in "GarageBand" to give your music an original sound and tie the different selections together. For instance, you can use preselected music to mix with your current songs and serve as an underlying track. Adjust the timing of each song as necessary.