Gdam123 also accepts ex-style input. A colon(:) initiates an ex command, which can be seen as it is entered. :help produces a full list of key bindings and ex commands. :a filename appends a file to the playlist. Directories and playlists can also be appended.
ex-style gdam123 key bindings
command : :volume n
action : set volume to n%. Volumes above 100% are allowed.
command : :set volume_delta delta
action : changes the effect of a volume nudge to delta%. Affects o,p key bindings.
command : :print
action : print playlist.
command : :append filename
action : if filename is an mp3 file, it is appended to playlist if it is an mp3 file. If it is a playlist, the contents are added. If it is a directory, the subdirectories are sourced for mp3 files.
command : :n
action : skip to the nth song.