Adult contemporary is essentially a continuation of the soft rock style that became popular in the '70s, with a few adjustments that reflect the evolution of pop-music production techniques. Adult contemporary has the same lush, soothing, highly polished qualities as soft rock, and it works the same "middle of the road" territory — in other words, it largely lacks the grit of even the slicker varieties of rock or soul music, but it's too indebted to those original sources to qualify as traditional pop or easy listening. The main dividing line between soft rock and adult contemporary is that the latter commonly features synthesizers (and other electronics, such as drum machines) as an important component of the music's smooth studio sheen. Both as a style and a popular radio format, adult c