# Concert sound

1. Nov 1, 2004

### primal schemer

Hi All,

I was at a small jazz concert the other day, and was sitting pretty close to the stage. There was a candle on the table i was sitting on, and every time the drummer hit a certain drum, the flame of the candle flickered. There were only three instruments on stage, and the effect occured even when the other two instuments were silent. Also, I looked, and it wasnt due to someone tapping their foot or anything like that. and it didnt seem to happen for any of the other drums / instruments.

My guess is something to do with the frequency of the drum being somehow related to the flame???

I guess we are all familiar with a large bass sound making the floor of a room vibrate (incidenty, the drum wasnt the low sounding 'foot' drum (I dont know the names), but one that he hit with the drumstick). Is this the same effect happening here????

Thanks,

PS

2. Nov 1, 2004

### Staff: Mentor

The frequency of a bass drum is so low that you can see both ends of the pressure wave go by. With higher frequency sound, the flame waves back and forth so fast (and therefore moves such a small amount) that you can't see it.