The cajon is a Cuban percussion instrument, shaped like a box (cajon can mean crate, box or drawer). It usually has one side thinner, made of hardwood, and snares attached to that side's inner face. One strikes either an adjoining side for a bass-drum sound, or, as with some modern models, the snares are installed at an angle on the front side so that both bass-drum and snare sounds are produced by slapping or pounding the front face of the instrument. the player is seated on top of the instrument and plays by reaching down to strike the surfaces of the cajon.

The problem with using the cajon in pop, rock or folk music contexts is that t was designed to play syncopated Cuban rhythm patterns such as samba. Therefore, people who are not Latin-style musicians hear the cajon played that way and then try to adopt the same syncopated, polyrhythmic techniques in the wrong musical settings.

One of the things that drummers can fail at is being too "busy", that is, playing so many accents and polyrhythms that they obscure the straightforward rhythm of songs, especially when accompanying vocals.

Imagine the difference between a straight-ahead marching meter and a New-Orleans "second line" beat, which is designed for dancing and as a means of improvisation during instrumental playing in groups. yes, there's a place for it, but the place is not all over every damned song in any contextwhich is where cajon playing fails.

There's also to be no rehearsal before I play at this church service, so the box-slapping fellow is just msant to listen and join in as appropriate, which, imo, is never.