Playing on the beat, behind the beat and in front of the beat

I'm always asked by students about this concept so here's a quick demo. This is not scientific and I know it's not exact and sometimes I make adjustments but I hope gives a idea of the different feels. It's for jazz drumming and the differences are very “behind the beat feel“ is more obvious then the “in front of the beat feel“. I'm playing along to the Allan Cox instructional CD “Meet the bass player“. It's “Rhythm Changes“,and I change every 8 bars and the tempo is 120 BPM