I get a lot of questions about how to play the accents on beats 2 and 4 in jazz, rock, and different types of pop music. (Thx Felise for today's question!)
The function of these accents can indeed be confusing for a while. We're usually taught that beats 1 and 3 are accented in traditional music, while in jazz and later popular styles beats 2 and 4 became accented. A lot of you sense that this is too simplistic and explanation and email me to clarify it for you. (Check out Beethoven's first piano sonata to see a classical example of accenting 2 and 4. He spends much of the 1st movement avoiding LH notes on 1 and 3!)
Here goes some explanation (big breathe!):
For swing music and post-swing rock and pop styles, yes, beats 2 and 4 are accented. They are played a little louder than beats 1 and 3 are. But at the same time, beats 1 and 3 are (ironically) still "felt" very strongly. So if you picture a trampoline, the downward bounce is on beat 1, and the spring up into the air is on beat 2. Same with beats 3 and 4.
I once did an arrangement for a Broadway show where the dancer needed to kick his leg up on beats 2 and 4, in a classic "kickline" dance style. I initially played accents on beats 2 and 4 to help him. But he asked me to play the accents on beats 1 and 3 instead. When I tried this, I was surprised to see how well it worked. The music supported the dance much better! It became clear to me that there was a relationship between my downbeat and his accent on beat 2. The same with beats 3 and 4. You hear it in hard rock and music too: the guitar will play strongly on beats 1 and 3, and leave a rest on beats 2 and 4 which are accented by the drums. (eg: "Walk This Way" by Aerosmith: da-da-da-da, da-da-da-da-da BOOM!)
Listen to some music and try to understand the relationship between beats 1 & 3 and 2 & 4. It's a little different in each music genre, and becomes more and more fascinating as you delve into it over time. A working understanding of tempo, accent, beat, and groove will help your piano playing in more ways that you might realize.
If you want to experience piano like never before, check out my piano improv video course. I'll also give you personal guidance every step of the way!