"i should have thought it was common sense that popular musicians influence the progress of every type of music"

After popular musicians adopted blues music from folk musicians, popular musicians often influenced how some blues sounded (when that was "progress" is a matter of personal taste). For instance, W.C. Handy's dislike of what he considered overly repetitive lyrics apparently helped cause the popularity of 16-bar blues with AAAB lyrics to drop off, once his publications were successful and influencing other writers of published blues tunes.