"half-strengths", loosely "greaser" or "rocker") is a German term describing a postwar-period subculture of adolescents – mostly male and of working class parents – that appeared in public in an aggressive and provocative way during the 1950s in Germany, Austria and Switzerland.
These Halbstarke had found prototypes for their fashion and style in American movies, e.g. James Dean in Rebel Without a Cause (German title: …denn sie wissen nicht, was sie tun) and Marlon Brando, as well as the stars of rock 'n' roll, that was gaining popularity then.
That same year Bill Haley & His Comets' song Rock Around The Clock reached #1 in the German Pop charts.
Rock 'n' roll offered tunes and rhythms that were revolutionary and a catalyzer for the youths' emotions and fears, unlike the then-popular but shallow genre Schlager.
On December 30, 1956, about 4000 juveniles walked through Dortmund's city, affronting passers-by, rampaging and having battles with the police, after a cinema show of Außer Rand und Band (Rock Around the Clock with Bill Haley).