First off, this requires NickServ on the server, and that /msg NickServ is the right one to send it to. Just using /ns or /nickserv would be better.
Second, this is not half as good as the Services addons/snippets that exists...

How about using nick changes to count some events. Like checking for away, afk etc etc in the new nick as many people tend to use their nick to tell everyone what they are doing... :)

Adding super simple in the title will most likely qualify as more or less useless... This needs more to stand out, I am guessing it is (or was) something like 10 snippets like these here on Hawkee.
Look at similar snippets and find features that will make yours stand out!

A bit too static and simple

@Lindrian Ohh, the image was a bit larger then expected. Delete if you like...

@Lindrian

@Lindrian set FURBY* best <--- It just returned: \'Impossible input\'. Go figure...

@Lindrian I didnt see anything wrong with that?

@Lindrian I rule...

@Lindrian I will also post a random comment here

It is also possible to allow the user to specify the music/mp3 directory, which I think would be the best way to do it...

I think this was originally my idea, but I used a real bomb. Strangely, no one found that to be fun...

You could clean up the code, like removing the halt as they are not needed here. Also, why do you use // as command prefix?
And dead also gave you a good tip on how to improve the code by atleast 2 points. But your general idea is pretty good, and I am seeing this could be useful to some ppl...

Its kind of personalized. There is no guaruantee that whoever dl this would have any of the same paths as you. You should really allow changing the paths if this is to be of any use. Maybe even add some empty buttons for more shortcuts.