I love rock and roll music.  Do you know much about the genre?
It's a genre of popular music that came about in the United States around the late 40s/early 50s, from African American musical styles, like gospel, jump blues, jazz, boggie woogie, and with some country music thrown into the mix!
So it has a lot of influences.  When was rock music the most popular?
Perhaps in the 1950s and mid 1960s, as this was the time when the "more encompassing international style" of rock music came about