The origin of "The Saints Will Never Come" from Left 4 Dead 2. This is a cover of "When The Saints Go Marching In" by Louis Armstrong. "Mike Morasky - The Saints Will Never Come" In-game version: youtube.com/watch?v=CI7DVKYFmKg #sourcemusicorigins
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Fun fact, "When The Saints Go Marching In" is actually a very common song played at all sorts of events ranging from festivals to funerals in New Orleans. New Orleans, of course being the setting of The Parish, in which you prominently hear this song.