His West End theatre work includes Enjolras and Javert in Les Misérables, Anatoly Sergievsky in Chess, Pontius Pilate in Jesus Christ Superstar, Orin Scrivello in Little Shop of Horrors, Agustín Magaldi in Evita, Munkustrap in Cats, and John Jasper in The Mystery of Edwin Drood.
Burt played the flamboyant Count Fosco opposite Yvette Robinson in Andrew Lloyd Webber's The Woman in White at the Palace Theatre (2005) and was featured as Captain Andy Hawks in Show Boat at the Royal Albert Hall.
He was among the only members of the original principal Les Misérables cast not to appear at the 25th Anniversary concert, claiming he would not be able to sing the part in the encore anymore.
Notable hijinks included handing a hard hat to an orchestra member during the bows, after accidentally sending a chair into the pit during Act 2.
In 2014 he appeared alongside Gina Beck, Daniel Boys and Eve Polycarpou in Jacques Brel is Alive and Well and Living in Paris at the Charing Cross Theatre.