Import your songs. To mash music, you will need at least two song files. After choosing your songs, import them one at a time by clicking "File," "Import," "Audio" on the menu at the top of your screen. Use the pop-up navigation to select your song files. Each song file will import to its own track, so you can edit it individually. Your tracks are the long, horizontal wave patterns on your project window and they function as individual layers.
Cut your songs as necessary. When mashing music, you will likely just want to use specific parts of each song. To cut up your song files, click the “Cut” button (the scissor button) and click the portions of each song you want to divide. For example, if you want to save the chorus of song #1 and remove everything else, make a cut at the beginning and the end of the chorus as it appears in wave form on the time line. That will isolate the chorus. You can then delete the sections before and after the chorus by clicking them and then clicking “Delete.”
Arrange your songs. In a music mash-up, you may want to jump repeatedly from one song to the next. To arrange your songs on their prospective tracks, just drag the horizontal wave forms with your mouse. Your time line appears above the tracks; use that as your guide. For instance, if you want to start the chorus of song #2 immediately after the chorus of song #1, use the time line to determine where the first should end and the second should begin. Make sure to keep each song file on its own track.
Balance the volume of your songs. When mixing different songs together, they will likely begin at different volumes. To bring the volumes into harmony, use the “Volume” sliders in the left column of each track. For example, if track 1 is much louder than track 2, reduce the volume in track 1 using the “Volume” slider until the volumes match.
Fade in and out for more natural transitions. For instance, if you jump from one chorus to another, the result may sound highly abrupt, but if you fade out of chorus #1 and fade in to chorus #2, it will sound more smooth and natural. To apply fades, highlight the wave forms you want to edit, such as the last few seconds of chorus #1 or the first few seconds of chorus #2, and then click “Effect” on your menu bar. Choose “Fade Out” to apply a fade-out effect or choose “Fade-In” to apply a fade-in effect.
Save your finished mash-up. Click the “File” menu and select “Export” to save your mash-up as a song file.