"When the War Was On" is a call and response blues song recorded in 1929 by Blind Willie Johnson and Willie B. Harris, who is thought to have been his first wife. Johnson plays bottleneck guitar, and sings throughout in his 'growl' (false bass) voice; Harris sings soprano. The war referred to is World War I (1914–18): this is clear from the references in the lyrics to President Wilson (1913–21) and the Kaiser; the USA entered that war in 1917. As of July 2015, it seems that the song has not been recorded by any other artists.