Cormac offers lessons in Southwest London and online. He started learning the cello at the age of seven. He studied at the junior department of the Royal Irish Academy of Music and was a member of the National Youth Orchestra of Ireland for many years. Cormac continued his education at the Cork School of Music and the Conservatorium van Amsterdam studying with Christopher Marwood and Jelena Ocic. He also had the opportunity to participate in masterclasses with artists such as Maria Kliegel, Roel Dieltiens and Raphael Wallfisch, and at the West Cork Chamber Music Festival with members of the Pacifica, Zaide and Appolon Musagete Quartets.

As an orchestral cellist Cormac has performed with orchestras in Ireland and the Netherlands, and he has performed at festivals in Ireland, Sweden, and as far afield as Korea.

Cormac has been an Ambassador for the Nicola Benedetti Foundation since 2021 and currently teaches at Alleyn's Junior School in Dulwich and Muswell Young Musicians in Muswell.