Going to see a live band is usually an exciting and enjoyable experience, and one which you will probably want to record with photographs. However the concert environment presents a lot of problems for the amateur photographer. The venues are usually dark, which means you need to use long exposures and/or high ISO settings, if you're in the audience there is usually very little room to move around and you're likely to be jostled by the people around you, which makes taking the picture difficult, and using a tripod is usually out of the question unless you have special permission. On top of that, the nature of stage lighting presents some special exposure problems of its own. As a result, most of the time you'll find that your photos of live music events are disappointing at best, and are usually a horrible mess suitable only for quick deletion.
However if you know what you're doing it is perfectly possible to take photos of live gigs that look good and capture the atmosphere of the event, and if you play your cards right they could even make you a little money.