We played a small beer festival last year and I went on stage plugged in and... nothing... turned the amp up again, checked everything was plugged in, di etc... still nothing. looked at the engineer who was scratching his head and twiddling with things trying to find out what was wrong. Silence from everyone else in the band and the crowd waiting for me to sort it out. A few more minutes faffing around then the engineer came on stage, checked everything, swapped out the DI etc... after another minute or so of head scratching I realised the volume on by bass was set to 0...