CREATIVE NOMAD Zen XTRA - Manual (Page 51)

Playing and Managing Your Music 3-12
5. Scroll Select Open. The tracks within the sub-category appear.
6. Scroll Select Add to Play to add the audio selection to the back of the
Selected Music List.
7. Scroll Select Play Now or press the Play button to add the
selection to the front of the Selected Music List and immediately play it
back.