In the musical of Frederick Loewe and Alan Jay Lerner Alexander took the lead role of 'König Arthur'.

In 2006 to 2007 Alexander played the 1. cast of 'König Arthur' at the Theater in Lüneburg/Hamburg. Director was Helga Wolf.

In 2007 Alexander was again to be seen on stage in the role of 'König Arthur' during the Sommerfestspielen Jagsthausen in the Götzenburg.

The Götzenburg is the castle of Götz von Berlichingen. The same named show of Johann Wolfgang von Goethe takes place annually.