If the Berlin brains theatre completely overhauled his musical “Line 1” almost exactly 37 years after the premiere, it is something like the restoration of a national cultural asset. Or at least an act of loving preservation of an apparently indestructible remnant from old West Berlin. When it premiered in 1986, the musical was a period piece from the rather gray present-day Berlin populated by the homeless, bourgeois, shabby bohemians and scrounging punks: “Haste mal ‘ne Mark?” Almost 2000 Grips performances later, it has aged into a history painting, a moral image from a lost world, when Berlin was not yet gentrified, the Zoo train station was the gateway to the world and Kreuzberg was not yet a hipster biotope.