What is in your gig duffle? Guitar tools strings 9volts strap (I used D rings and use the extra strap on my gig bag) Amp cord Extension cord Flashlight Gaffers tape Towel Fuses instrument cable Plectrums Gas card Stings for your guitarist Drum sticks Drum key Nail clippers How about you
Aspirin and band-aids one thing that saved a gig once—a soldering pencil and some solder a small VOM found 110 volts between guitar strings and microphone once, and I try to carry a small polarity tester.