The controller buttons act just like the controls on most CD players:
To select the Next song, single-click the Forward button (double arrows pointing to the right).
To Fast Forward the current selection, press-and-hold the Forward button.
To select the Previous song, single-click the Back button (double arrows pointing to the left).
To Rapid Rewind the current selection, press-and-hold the Back button.
The middle button toggles between Play and Pause when a song file on your computer (or on a CD) is playing.
The same button toggles between Play and Stop when the Radio Tuner is active.