No outdoor event will be successful unless it has access to sufficient power and electricity supply and distribution. This is especially true for a musical event which makes use of a great number of electrical devices, some of which consumes a lot of wattages. The electrical setup for any major event, especially one which is projected to consume a great deal of power and involves complex wiring and power distribution should only be attempted by professional electricians.
Whenever you are setting up for an outdoor musical event, it is always preferable to find a connection to the main power grid whenever you can. It is far more reliable than using standalone generators, and are far more convenient. Many outdoor venues and stages are equipped with power sources that the performers and their crew can readily access and tap into. However, it often happens, when the venue is a building that is not built to be a live stage, that there is no convenient access to a power source, even if sufficient power is being fed into the building. In this situation, before you go and hire generators, you might want to consider installing a dedicated power socket. This requires a bit of negotiation with the owners of the site, gaining their permission and agreeing who would cover the costs, but with any luck, approval can readily be gained.
The reason for the necessity of such an installation is because ordinary wall sockets may not be safe enough to handle the power needs of all the equipment that needs to be set up for the musical event or concert. Otherwise, you may be dealing with overloaded wall sockets and the very real risk of electrical fires.
If there is no readily available electrical source, the only recourse you have is to hire generators. These are usually powered by diesel engines, and generally reliable. But there will always be the possibility of a power failure or insufficient power supply, so when hiring generators, make sure you also provide backup generators to cover possible emergencies. A professional electrician will be able to set things up so that backup generators can immediately kick in should the primary generators fail. All the electrical equipment needs to be set up properly so that no undue damage to the electronics will result should power failures take place. Power breakers should also be put in place to guard against damage or danger in case of overloading or short circuits. Additional safety measures that need to be taken include grounding equipment and RCDs or Residual Current Devices, both of which guards against stray currents.
Finally, to ensure the efficient supply and distribution of power to all the necessary electrical equipment needed during the musical event, electricians will have to sit down and make calculations on the basis of a list of all these equipment, what the projected power consumption and power supply will be. The available power must be sufficient for the volts and amps, the cables and wiring utilized must be relevant to the measure of current that will be passing through them, and the entire electrical setup must be designed so that amps go up should the volts drop.