Viola player Cian Ó Dúill was a founder member of both the Regent String Quartet and the Rothko String Trio, and is currently a member of the Solas Quartet.

Cian was co-principal viola of the London Mozart Players and worked regularly with the London Symphony Orchestra, Mahler Chamber Orchestra, Orchestre Revolutionnaire et Romantique, Orchestra of the Age of Enlightenment and the Britten Sinfonia.

He teaches viola and prepares students for professional auditions.