The Shure SM58 is a popular and widely used microphone for live sound. It is renowned for its durability, reliability, and great sound quality. Its frequency response is tailored for vocals, with a brightened mid-range and a bass roll-off to reduce proximity effect. The SM58 also features a cardioid pickup pattern, which helps to isolate the sound source and reduce background noise. Additionally, it has a pneumatic shock mount to minimize handling noise. Overall, the Shure SM58 is an excellent choice for live sound due to its ruggedness, excellent sound quality, and effective noise rejection.