Popular Help>Play | Manage | Copy | Customize
To play music files such as MP3, mp3PRO, WAV and WMA; you must first create a playlist, that you can also save and open for later use.
Selecting the menu View>Playlist will open the Playlist window if closed.
Highlighting a track in My Library and clicking the Play button adds that track to your playlist and starts to play, or you can drag and drop files from My Library into the Playlist window.
See also
Play Reordering (shuffle and repeat tracks)