Well, if you want to get technical..
"What are some of the technical differences between rock 'n' roll and rock?
Chris Xu
From a purely musical standpoint, rock music is an umbrella term to describe music typically characterized by a persistent, strong drumbeat and amplified (often distorted) electric guitars.
Rock and roll is a subgenre of rock music which evolved in the early 1950s from Chicago blues, jump blues, and big band swing.
. Musically, it is defined by three major characteristics:
- An overt blues influence. having evolved from several genres of electric blues, rock and roll often recontextualized classic blues harmony - as well as chord and musical structures - in a louder, more upbeat setting. The most obvious example is the 12-bar form, one of the most common blues structures in existence, which is often incorporated verbatim by artists such as Chuck Berry. Even though rock and roll quickly transcended this one structure, overt blues musical vocabulary (scales, inflections, lyrical subjects, etc.) remains prominent.
- 2. Syncopation and swing. Early rock and roll rhythm sections were descended from the rhythm sections of swing bands that played dance music in large halls. This “swing feel” remains a defining aspect of jazz music. Swing rhythms are often defined by constant, subtle hi-hat pulse on beat 2 and 4 of every measure. However, early rock and roll drummers swapped the hi-hat in favor of the snare drum, which gives a heavier rhythm. If you listen carefully to old rock and roll records, you can often hear this altered back beat (combined with walking bass)
- The ideas of syncopation and swing lead me to my last point, and what I think is probably the most important, defining aspect of rock and roll, which is a rhythmic tension between the guitar and the drums. This push and pull is what gives rock and roll its groove. As I mentioned, early rock and roll rhythm sections were descended from jazz rhythm sections, often incorporating danceable jazz drum patterns and walking basslines. However, rock and roll guitarists, namely Chuck Berry, played “straight” (the opposite of “swing”) over said rhythm sections. This combination of straight-eighths guitar rhythms over a swinging rhythm section gives rock and roll its rhythmic tension. Listen back to the example in point 2, this time focusing on the driving guitar and how it butts up against the swinging rhythm section.
Over time, as rock grew into its own, drummers lost their jazz influences and took up a stiffer, more powerful approach that would compliment increasingly loud and distorted guitars. In this newer approach, the drums retain a simple backbeat that slightly drags behind the beat while the guitars play in a much more syncopated manner. While the jazz rhythms are discarded, the swing feel somewhat remains via this “behind-the-beat” approach, while the guitars emphasize the upbeats much more, where the drums are not. Rock and roll rhythm sections understand not to follow the guitars verbatim, and do not feel the need to emphasize every chord change. This is a big difference from modern rock and metal styles, where the guitar, bass, and drums are locked in together playing in one
downbeat.
- -heavy rhythmic unison for a more powerful sound. Rock and roll makes people dance through rhythmic diversity, which creates tension and groove.
