A Fraction of a Second...
Updated: Oct 21, 2019
...makes a huge difference.
I visualize the beat as a circle with a dot in the center. There is a certain latitude concerning where within this circle you can play and still be considered to be "in time."
You can play in the center of the beat - right on the dot. Thus, "on top of the beat."
You can play in front of the dot. Thus, "pushing the beat."
You can play behind the dot. Thus, "behind the beat."
Most players play where they play intuitively; they think of it in terms of "feel."
Whether "pushing" or playing "behind," you're still on the beat, you're just on the frontside or the backside of it. In my opinion, where you play within this circle is mostly the result of what you've listened to during your formative years. If you miss the circle altogether, you're "out of time."
A lot of Blues and Jazz players play more-or-less behind the beat; that's one of the things that gives that music its swing. Of course, Classical musicians are very precise - right on top of the beat. There are many country musicians who play on top of the beat. Country swing feels different than the kind of swing found in Jazz and Blues for this reason (among others).
BTW: playing behind the beat isn't less precise - it's precisely a hair behind the beat!
So...Blues-influenced Rock guys tend to play a little behind; Classically-influenced Rock guys tend to play more on top of the beat. That's the difference, for example, between a band like Aerosmith or Led Zeppelin and more Classical music-influenced Rock music like Yes, Emerson, Lake and Palmer or King Crimson.
I regularly play with a bass player who pushes a little bit.
There are all kinds, and drawing a correspondence between a feel and a genre is a gross oversimplification. For example, Jazz/Blues guitarist Robben Ford plays right on top of the beat; dead center. That's as opposed to, say, John Scofield, who plays waaay behind. Many times, you have both types of players in the same band. The 80's-era King Crimson with Adrian Belew (behind) and Robert Fripp (on top of) for example. I loved that version of King Crimson; the contrast between those two guitar players was one of the things that made it interesting.
Usually, someone in the band plays on top or pushes a little bit and the others fall into their respective positions relative to that.
Good drummers can do both; one or more of their 4 limbs will occupy different points in the circle.
I'm more of a behind-the-beat type player; that's where it feels good to me.
Here are a couple of anecdotes that illustrate how all this can work out on the gig, and also how a conscious awareness of this phenomenon can defuse a band fight.
The incident where, for me, this stuff moved from intuition to a more cognizant apprehension of it was on a variety gig. I can't remember the function; wedding reception? Corporate gig? I don't know, but the point is it required a wide variety of material.
The instrumentation was guitar, bass, drums, saxophone and a lead singer/frontman. No keys. The drummer was a sub that nobody knew and none of us had played with him before.
The first set was pretty painful. Everything kept slowing down. At one point the singer turned around and said, "If that song had lasted a couple of more minutes it would have come to a complete stop!"
I was thinking to myself, "It's gonna be a long night."
It was actually the singer who figured it out. He took me aside on the first break and said,
"Look man, I think this drummer is used to playing in rhythm guitar-driven rock bands. You need to play like Keith Richards. You need to be the one to maintain the tempo."
I got it. I knew that I liked to play behind the beat. If the drummer was getting his cue from me - and apparently he was - he was getting the message that I was telling him to bring it back a hair. He would adjust, and then I would adjust to stay behind, where I was comfortable, he would adjust, I would adjust - and that's why everything kept slowing down.