Lena Ashwell was a music teacher at Benenden School who had taken part in concert parties for the troops in WW1. I have long intended to find out more about her, and am delighted to see that Kate Adie has now published a book, featured in this Daily Telegraph article: http://www.telegraph.co.uk/history/world-war-one/10757403/LenaAshwell-the-woman-who-brought-music-to-WW1-trenches.html