Over the years the music for this ubiquitous Christmas song has been erroneously attributed to plenty of famous composers, including Haydn and Beethoven. But the true lyricist was unknown until as recently as 1995, when an 1820 manuscript was discovered that confirmed the men behind the song. The song was actually written by two Austrians: one named Franz Xaver Gruber, a primary school teacher, the other Joseph Mohr, an assistant pastor at St. Nicholas Church, in Salzburg. In 1816, Gruber started a side hustle as choirmaster and organist at the church when he quickly decided to compose a new hymn for the congregation to sing. The two created Stille Nacht.To be clear: Mohr wrote the lyrics and Gruber composed the music. The pair performed their masterpiece for the first time at Christmas Mass in 1818, with Gruber on the organ and Mohr on guitar. The song went mini-viral (at least in 19th-century terms) when an organ builder who serviced the church’s organ fell in love with the song and spread the word about it to other churches. It was picked up by two popular traveling families of folk singers around 1931, the Strassers and the Rainers, after which it only gained in popularity.