Much of this reggae "history" is included in the
notes for Reggae Music: The Golden Era 1960-1975 and to
today's reggae music.
Alongside the tiny manufacturing industry, there were
open-air deejays known as sound systems. A cliff
face of speaker boxes, each big enough to raise a family
in, powered by amplification of intercontinental capability."
There was life-and-death competition among the system operators
source the rarest American R&B and the best technology.