Joy was born in Glanamman, Dyfed. Whilst still at school, she won a scholarship to have piano tuition at the Welsh College of Music and Drama, Cardiff, before entering the University of North Wales, Bangor, where she studied with the Czech pianist, Jana Frenklova.

After graduating with an honours degree in music, she took a post-graduate course at Trinity College of Music, London, where her tutor was the distinguished Hungarian pianist, Joseph Weingarten.

She was appointed Accompanist to the Morriston Orpheus Choir in 1991 and her expertise in that role has been widely recognised. Beyond the United Kingdom, she accompanied the Choir and its guest soloists in Australia, Canada, Eire, New Zealand, Oman, Poland, Spain, Taiwan, the United Arab Republics and the USA, including performances at the Sydney Opera House and Carnegie Hall, New York.

In 2004, Joy was made a Life Member of the Morriston Orpheus Choir in recognition of her outstanding contribution and commitment. After 16 years as Accompanist, she was appointed Musical Director in June 2007. Joy conducted the Choir at many prestigious events, including the Somme Centenary Commemoration Service in France in 2016. Joy retired from the MD role in 2021 after 30 years of devoted service to the Choir.