These were a
fad back in the
80s, when small radios that could be played loudly were still a
novelty. It was
trendy to walk down the street with one
blasting out your favorite music. By
stereotype, this was
Rap music or
Funk, but back in
Wisconsin, my friends and I preferred
Whitesnake and
Van Halen.
The fad petered out after the advent of the walkman, which was a lot easier to carry. Boom boxes are still made and bought, but they're usually bought by people who are truely interested in portable audio at picnics or at the office, and not by people trying to offend people on the street, which was the case in the 80s.
Incidentally, the street gang stereotype gave the boom box the nickname 'ghetto blaster'.