You don't need any scripting to display the current song in a conversation, you can use the tag (!MYMEDIA) for that.
Thus in a conversation, type for example:
Hello, I'm listening to (!MYMEDIA) at the moment.
and that tag will be replaced with the current song when you send the message.
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There are however scripts which add some more options to this. eg:
Music Now Playing from -dt- will add the old (!WAT) tag with some more options
http://www.msgpluslive.net/scripts/browse/index.php?act=view&id=58
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If you need something which will show the current playing song in your nick, I don't think there is any script yet to do it. But it would be very easy to make.
Although there is a restriction in Messenger in how often you can change your nick in one minute! Also, it might be annoying to your contact if you show the current playing song in your nick (and thus you change your nick often). For this, there is the personal message, and in that regard, you don't need anything for the song to be shown.
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