In addition to his work as a performer, Ruairi has also established a distinctive voice as a composer drawing on his eclectic musical background and flair for different musical traditions from around the world. He composes music for his group Tir Eolas who are regularly heard on both concert stage and radio.
Ruairi is particularly inspired in the process of collaborative composition, and has facilitated workshops to develop new music with a variety of different groups, from school children, young people on the autistic spectrum, refugee groups to adults living with dementia. In 2015 he was commissioned by English Touring Opera and Turtle Key Arts to create a new song cycle with people living with dementia to be premiered in Fairfield Halls, Croyden. Ruairi has composed and music directed a number of productions for Chickenshed Theatre Company including We Are All Born Free, a collaborative project with Amnesty International, the title song of which was performed for the Dali Lama's visit to London in October 2015. Ruairi regularly presents live orchestral concerts which feature his own orchestrations and arrangements of classical repertoire, often condensed for smaller groups of musicians and featuring participatory elements.