When I strike an open note on my electric bass the corresponding note on my double bass sounds, and it resonates. Since my double bass still hasn't been set up this is quite a nuisance... Last night I was in drop C on my electric for kicks, and I cranked up my amp, and I let the C go, and the G string on my double bass was going crazy. It was literally flapping back and forth over the area of about an inch... I'm curious as to why this happens... just a chance to educate myself on acoustics or something... So why does this happen?