down-beat, backbeat

From This is Your Brain on Music, The Science of Human Obsession by Daniel Levitin I find this quote worthy: When people clap their hands or snap their fingers with music, they sometimes quite naturally, and without training keep time differently than they would do with their feet: They clap or snap not on the down-beat, but on the second beat and on the fourth beat. This is the so-called backbeat that Chuck Berry sings about in his song "Rock and Roll Music". This may also help to explain why sometimes you get out of sync if you try to watch another to keep the beat. Don't follow, just listen to the music. They may be on the "backbeat" or another beat altogether.