For version 7 you can use the debug mode to modify the layout of a playlist.
in this post there is a complete tutorial on how to work with the debug mode:
Please note:
[*] Playlist skin: “Custom” columns renamed to “Dynamic” columsn (Dynamic1 etc.)
to work around naming conflict with “Custom1” etc. playlist item types
Thank you all! Another question and maby i overlooked: the default in a playlist is that i need to click on the arrow to see text i put in the description for that song. Where can i change it so the text is always visible without first needing to click on the arrow?
Unfortunately this functionality is no longer available in version 7 (big problem for me…).
But according to Torben it will be implemented again in a later update.