To start off in this business, you'll need to invest in instruments and equipment, from your basic electric guitar to keyboards and drums to sound systems. It helps if you have some experience working for a band or similar business so you'll know what kind of set up your customers will need. It won't cost you a bomb to set up if you know where to get quality used instruments. Then you'll need to find a shop somewhere with enough space to store your equipment. You could convert your garage into your store, but for a more professional image, you'll want to be somewhere easy to reach. You'll also need a van to transport the equipment to your client's place. Remember to get a deposit from your customers. This is a necessity to cover "accidental" damage. You might want to cover your instruments with insurance so you don't end up losing money if the equipments gets totaled or stolen. As your business grows you'll want to increase your inventory of equipment so people will know they can get anything they need from you. Can you hear the cash register ringing already? Music to your ears isn't it?