HUSTEN, you can certainly do this following the guidelines for creating Namespace Templates and placing 'relative' links in the template in order to link to the sub-pages. (See the 'aside' below in regard to namespace/page naming.)
Place the following markup into your page named: bands:aerosmith:main
Menu: [[.:main | Main Page]] [[.:discography | Discography]] [[.:members | Members]] [[.:live | Live Concerts]]
Note the use of .: in the links to create 'relative' links to the current namespace. See DokuWiki Namespaces
You may also want to add any common headings or sections into this page as well as the menu links (as this will be your template).
Now follow the instructions on the Namespace Templates page to copy /bands/aerosmith/main.txt
to /bands/__template.txt
(note the double underscores which will make the template apply to all sub-namespaces within the 'bands' namespace).
Now, whenever you create another band page, such as bands:red-hot-chilli-peppers:main, it will automatically be populated with this menu of links to the other pages (and you have the benefit of just clicking the link in order to create the page).
A brief 'aside' in regards to DokuWiki pages and namespaces:
If you create a new 'page' named bands:aerosmith
then you end up with a Namespace named 'bands' which contains a Page named 'aerosmith.txt'
But if you create a new 'page' named (note the trailing colon) bands:aerosmith:
then you end up with a Namespace named 'bands' containing another Namespace named 'aerosmith' which contains a Page named 'start.txt' (if you haven't changed the default page name in the configmanager).
So, if you use my instructions above, you will end up with a Namespace named 'bands' and a Namespace named 'aerosmith' and a Page named 'main.txt'. BUT you do not have a page named 'start.txt' so if you attempt to browse to /bands/aerosmith then you won't see the 'main' page as it will (by default) attempt to show you the 'start' page in that namespace.