I feel that rock music has always been there as a forerunner. It has just taken a newer shape. It used to be some harder drums and some electric and you just went at it, (Beetles, Presley). Then took a more orchestra like form, (Led Zepplin, Pink Floyd). More electric effects and drama were put in as technology evelved, (Whitesnake, and others like them). Then slowly evolved into a harder form called metal. We had bands like Metallica, Pantera, etc. Now a form called alternative is introduced. We had the trend of bands such as Nirvanna, Foo Fighters, Green Day, etc.
From these and other forms (ska, indutrial, rap, R&B) We have the newer rock.
I like what has become of the evolution of rock.
Music is constantly developing and forming new styles.