Williams appeared with most of the greatest conductors of his time, including Arturo Toscanini, Bruno Walter, Otto Klemperer, Sir John Barbirolli, Sir Adrian Boult and Sir Thomas Beecham. When in England he sang in every season of Sir Henry Wood's Promenade Concerts in 1921-51. An acclaimed performer in Elgar's oratorio "The Dream of Gerontius", Williams often worked with the composer. He sang at Elgar's memorial service in 1934 as well as at the coronation of King George VI and Queen Elizabeth in 1937.