We do allow musicians to plug into our sound systems with a few restrictions.
Our sytems have one XLR input and one 1/4 Jack. So two outside sources.
If a microphone is needed, then only one instrument can plug in.
If you have more than one mic needed or more than one instrument you will require a mixing board. We do rent these for $65.
Any musician plugging in should bring a DI box with them. If they plug in and there is a buzz, we will unplug them.
We do not allow kick drums to be mic'd.
You may want to forward this to the musician, they will understand what is needed. It may sound complicated but it is very simple and better than having a second sound system there and incurring extra charges.