The songs sung by music hall artists during the First World War were often filled with war fever and patriotism.
Sons of Australia was written by prolific English music hall composer Felix McGlennon in 1900, during the Second Boer War.
Prior to radio, songs were largely heard performed in music halls. People would then visit music shops to purchase the sheet music of tunes they liked.
When the War is Over, Mother Dear was recorded at all is a testament to its popularity at the time.