My first concert was Kraftwerk, around 1970. They played at our place in Reinbek (Hamburg East) in the auditorium of the Sachsenwald-Oberschule (SOS).
The auditorium was packed. On the stage the musicians sounded with exotic instruments. I was 13 years young at the time and found the concert to be rather horrible noise, until I saw the reaction of my music teacher sitting next to me. His eyes rolled back and forth frantically under his eyelids, then he jumped up angrily and left the venue gesticulating wildly. After this event, I didn’t think the music was so bad anymore.