Find "Music player"
Press the menu icon.
Press Music player.
Create playlist
Press the drop down list at the top of the display.
Press Playlists.
Press the Menu key.
Press Create playlist.
Key in a name for the playlist and press OK.
Add audio files to playlist
Press Add music.
Press the required audio files.
When the box next to an audio file is ticked (V), it's selected.
Press Done.
Exit
Press the Home key to return to standby mode.