sorry!!! I don't know why it doesn't work. The Url is absolutely correct but I always get a failure.
If I write it in the adressline like this:
http://www.stuttgart.onlinehome.de/lmusik.htm
it works without no problems but not so if I try to link it. Anyway you can find it this way too. There's lots of links to places with concerts and events of all kind from Stuttgart and the region around.
But the most of them havn't already put their dates for in. You probably should check them again in some days.
Hope I could help a little. I try to find more.
menzze