Could you please give me a website where I can see what is on when I visit Sydney, I have looked at ticketek but would like something where I can insert my dates and also plan my trips to coincide with a specific event.
You could try http://www.au.timeout.com/sydney/
This site you can see the events by the dates although i am not so sure how many concerts are on.
http://www.sydney.com/things-to-do? also has a fair selection of things, depending on what you want to do.
Google is your friend.
Pretty sure this one is what my wife finds stuff for us to do on.