Launch Adobe Audition and choose View > Multitrack View. (If this is the first time you are launching Adobe Audition, Multitrack mode opens first, with initial loop files. If this happens, choose File > New Session and do not save the initial session.) In Multitrack mode, you can mix up to 128 different audio tracks, including tracks from video files you have. Select Track 1 by clicking in any empty space on that track, and choose Insert > Video From File. Choose the video file you want to augment with music and click Open. Adobe Audition places the video on Track 1 and places the audio on Track 2. You also see a window that displays your video so that you can watch the video as you edit the audio.

You can include footage from only one video per session, but you can mix the audio from several videos in a session, up to the 128-track limit. To mix the audio from several videos, select an empty track and choose Insert > Audio from Video File.

Looping a sampled audio file is the quickest way to create a seamless music soundtrack, and Adobe Audition makes it easy to combine several files of this type. A short audio file works best for loops. To import a file for looping, right-click the next empty track below the video track and choose Insert > Wave From File. Adobe Audition imports the file at the location of the cursor on the track. Right-click and drag the imported file to the location where you want it to begin playing, in relation to the audio track in your imported video file.

To import one of the installed Adobe Audition files, navigate to the program directory and choose a .CEL file from the Audition Theme folder. A .CEL file is an .MP3 file with modifications to it that make it suitable for looping. Adobe Audition includes several such royalty-free .CEL files. In addition, there are roughly 2,000 other loop-ready files on the supplemental CD included with the product.

Select the imported file and choose View > Loop Properties. In the Wave Block Looping dialog box, make sure that Enable Looping is selected. (If you imported a .CEL file, it is already enabled for looping.) Set the time ruler to display in bars and beats by choosing View > Display Time Format > Bars And Beats.

Aligning your looped audio files is easier when you choose Bars And Beats as your time format. This allows you to time your music according to the number of beats the passages have. See Adobe Audition Help for information on using the Bars And Beats time format.