The Shure SM57 is a common professional low impeance cardioid dynamic microphone in live sound reinforcement and studio recording applications. It is a popular choice among live users due to its sturdy construction. It is often used on instruments that produce high sound pressure levels, such as the snare drum and other percussion, electric guitar amplifier, and, sometimes for vocals (even though it was not designed for that purpose). Introduced in 1967, the SM57 remains one of the best selling microphones in the world today. The SM stands for Studio Microphone.