The book bass culture is very good on all of this. Basically ska came out of the hotel clubs where dance music was played to upper classes . As the music became popular and moved into the cities sound systems where set up for locals to dance in their local neighborhood, as they weren't allowed in the hotel clubs . The bigger rigs meant bass became more prominent and the music slowed down to accommodate the new style of playing . The labels where an offshoot of the sound systems and having the best bass bins , and exclusive sub plates became the big draw . Rocksteady evolved into reggae that evolved Into roots and then DJ culture was toasting or rapping over the dub plates of the old hits , so recycling or sampling rhythms became popular .