Let's say that my favorite singer is coming to my city soon.  Ofcourse
most concerts are promoted through flyers, handbills, etc.  How can I
find out who is promoting the concert (concert promoter, sponsors) and
in what ways are they promoting the concert? (promo flyers, radio,
etc.) I'm looking for promotional flyers, pictures and additional
information about upcoming concerts that I can view online.

Let's take for example:

LL Cool J is on tour right now.   I've been to his official website
and there's info up there about the tour but it gives no information about
who is actually promoting his tour and shows no official promo stuff of the tour.

I basically want to be able to take any concert or tour,
find out who's promoting it and go to the website of the promoter to
view the "official" promotional stuff of the entire concert tour
and/or find the promo stuff for a specific tour date.