He designed Shakespeare at the Old Vic but his greatest love was opera, and he worked with some of the most eminent names in opera production, including Tyrone Guthrie and Carl Ebert. His designs for Sadler's Wells included Guthrie's famous Carmen, Pagliacci, Simon Boccanegra and Dido and Aeneas. He was for many years associated with the Wexford Festival, where his designs included Ernani, Count Ory, Lucia di Lammermoor, Gioconda, Don Quichotte and Lucrezia Borgia; in Belfast he designed and also directed a particularly effective La Grande Duchesse de Gerolstein. He also designed productions for the Netherlands Opera, and was for many years resident designer for the Arts Council's Opera for All.
His ability to create on small stages the illusion of Grand Opera entranced audiences throughout Britain. His designs for my 1968 production of The Dialogue of the Carmelites had the very young Kiri Te Kanawa in the role of the tortured Sister Blanche. Stanley Sadie, reviewing the production, commended Reggie's 'strongly atmospheric' sets.