Tough call - In Australia (notwithstanding that entire male communities volunteered there was a very strong anti-conscription movement under the direction of Irish Catholic Arch-Bishop Daniel J Mannix, and as I recall there was at least one song on the subject during WWI. John Lahey's "Australian Folk Songs' had a song about Mannix which goes something like "We welcome you back and we greet you with pride, you're the man who defied all danger" (presumably demonstrating against conscription).

As a complete guess I would suspect that very few homes would have owned gramophones at that time, probably restricted to the wealthy listening to classical music from the likes of local darling Nellie Melba. There was also no radio broadcasting until after the end of WW1. It is outside your friend's terms of reference, but the most likely (commercial) dissemination would have been via the sale of sheet music.

Still backing my judgement - Mannix's most powerful form of propaganda would have been via the Catholic Advocate newspaper, a very potent form of communication until very recent times.

Regards John