"When the Saints Go Marching In", often referred to as "The Saints", is an American gospel hymn. Though it originated as a Christian hymn, it is often played by jazz bands. This song was famously recorded on May 13, 1938 by Louis Armstrong and his Orchestra.The song is sometimes confused with a similarly titled composition "When the Saints are Marching In" from 1896 by Katharine Purvis (lyrics) and James Milton Black (music).