If you need to cancel it is not a problem. One would hope that you would provide as much notice as possible so that Jay could potentially book another event, but it is understood that sometimes things happen that can force a cancellation.
This is dependent upon your event and the type of music that you’re interested in booking. Typically, a few months out should be fine. But, if you are planning for a the summer or holiday season you may want to consider months in advance in order to have the best chances of availability.
This depends on the type of event. For concerts or festivals, a standard performance time is 60-90 minutes. For private or corporate events, Jay can play anywhere from 1-3 hours. More than 3-4 hours of performance time can be possible but is strenuous, so if you do book live music for that amount of time, he will require adequate breaks.