Let me tell you, there is so much truth to that line! You can listen to all the first rock n' roll songs and learn the blues guitar riffs, chord progressions and scales being played, just in a less bluesy kinda way.

"Johnny B. Good" is a superb example of a blues guitar progression being played with a rock drum beat and a vocal melody that is new from how a typical blues melody would sound. It doesn't finish there though. The influence on modern music is still really prevalent. We hear it in hip-hop, rock, emo, indie, reggae, r & b, funk, etc

The popularly used 1 - 4 - 5 chord progression (3 chords) that is used in blues is also used in practically All type of music that exists. Even Mozart uses this chord progression as well as many others from the classical period. Not only do blues guitar licks and chord progressions gets played in modern music, but almost all guitar solos also have blues overtones in country music as well as the other styles that I mentioned. It has been a Essential ingredient in molding the shape sound of modern music no matter how you look at it.

Learning how to play the blues should be a top priority on any guitar players 'to-do' list. Once you learn the ins and outs of this style, you can manipulate it to create your own classic songs, riffs and/or solos. Many guitar players that I know improvize on the blues scale to create their key riffs and super amazing leads as well as use the chord progressions to write novel, more modern music.

Don't allow anybody assure you that the blues is dead!