0_Apprentice
I love rock and roll music.  Do you know much about the genre?
1_Wizard
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!
0_Apprentice
So it has a lot of influences.  When was rock music the most popular?
1_Wizard
Perhaps in the 1950s and mid 1960s, as this was the time when the "more encompassing international style" of rock music came about
0_Apprentice
Is rock and roll still popular today?  
1_Wizard
It's hard to say. However, radio stations have much success playing classic rock and roll, which is a sub genre that usually has one or two electric guitars, a double bass or string bass or electric bass guitar, and a drum kit.
0_Apprentice
I used to listen to the rock band Rolling Stones.  Are they still around today?
1_Wizard
They are! Even though they were formed in 1962 and have had a long list of line-up changes, they're still around today, with Mick Jagger still leading the band.