Ir seems to me that the link doesn't answer Anna's question.

In my opinion, (tell me if I am wrong): 

<em>Not only is the music good for a party</em>....is telling us that the music can be good for something else as well,  for example for learning how to dance.

<em>Not only the music is good for a party</em> ....tels us that something else can be good for the party too, for example the decoration of the place.

Also, in Jack's example: <em>  </em>I would have expected the word "also" or "too" in the second part of the sentence: "<em>Not only is their music great to listen to, but their lyrics can be used to improve English too."</em>

<em>
</em>

Please correct me if I am wrong!

Hey jude, don`t make it bad♫♫♫...

Hi Anna, this grammar page explains quite well the construction of 'Not only...but also'

http://www.grammarly.com/handbook/sentences/parallelism/4/parallelism-with-not-only-but-also/

A nice article :) I just read it because I'm a big fan of The Beatles :)

Please explane: Not only is their music good for a party.

Why it can not be used like this: Not only their music is good for a party

Thanks in advance