With this extension, you can:
#!/usr/bin/tclsh require package xmms xmms playlist [glob /music/mymp3s/*mp3] xmms position 5 xmms play
All from the convenience of your favourite tcl-enabled application (AOLServer, for example). It provides all of the xmms_remote_* methods (xmms-1.2.5 version, 1.2.7 adds two extra which are not yet implemented).
It also makes building a custom user interface very simple, you can register an 'onchange' handler which will be called when something in xmms changes, like the current file, position, volume, playback state, etc. TkPlayer is a sample custom UI (very simple, mind you) - it lets you script your playlists to your hearts content, register callbacks for important changes (like scheduling new songs when the playlist reaches its end), it keeps track of when a song was last played and for how long, this will avoid hearing a song twice in a short period. When you use TkPlayer, make sure shuffle/random play is disabled in xmms.
You can read the full man page for xmms tcl here http://pascal.scheffers.net/software/xmmstcl to get an idea of the things you can do with it.
You can download the tcl xmms remote control source from http://pascal.scheffers.net/software/