(I use "seems" and "appears" a lot because most of the material I've found is in German, which I don't speak, other than basically "braunschweiger" and "bitte." Using a few English articles and services that translate web pages, I've been able to piece together as much as I could.)
I've come across some video of the musical in montage sequences that the cast performed on TV specials, but what I've embedded below is a music video they put together of the title song, "Hinterm Horizont," (Beyond the Horizon). I like it because it features Udo Lindenberg himself singing the lead along with the beautiful Josephin Busch who plays the female lead in the show. Serkan Kaya, who stars in the show, doesn't get to sing in the video, but he appears in his stage role as a fictional Lindenberg in the "story" part of the video. It's also an appealing number with an affectionate melody.
As far as I can tell, the show (which the video follows) is about a fictional Romeo-and-Juliet love affair in the 1983 between a young West German "Udo Lindenberg" and an East German girl, Jessy, which hits a hurdle because of the Berlin Wall.