Osian Gwynn Ellis was born in Ffynnongroew, Flintshire, in 1928, the son of the Rev. Tomos Ellis, a Welsh Methodist minister, and his wife Jenny (née Lewis), a harpist, and spent the first four years of his life at Llys Myfr on Llinegr Hill. As a boy Ellis was obsessed with playing the harp and playing football. In 2018 he recalled: “I chose the harp because we had one at home. My mother, Jennie, was a good amateur harpist... We did spend some years living in Denbigh and I was the goalkeeper for Denbigh County School. The boys used to say I was better at football than the harp! I taught myself to play the harp to some degree and was encouraged by my mother. We played lots of little concerts around Denbigh during the war. I also had a wonderful teacher Alwena Roberts, who taught students right across North Wales."