Hislop had a lyric tenor voice with a richness and boldness that could sound fuller and more thrilling than a typical robusto. A critic of Musical Opinion (a British magazine) went so far as to propose Hislop as the natural successor to Caruso. Hislop had a most un-tenor-like appearance: He was a slim 5'9" or 5'10" man with a long face. He moved from his native Scotland to Stockholm as a photoengraver's assistant. There he studied voice with Gillis Bratt and debuted at the Royal Swedish Opera as Faust in Gounod's opera. He rapidly became a star of that opera house, then was given leading roles in Italian operas at Covent Garden. He specialized in Verdi and Puccini operas and in Faust. He first appeared with the Chicago Opera in the 1920 - 1921 season. Later in his career he began taking leading roles in operettas, and appeared in several motion pictures. He returned to Sweden in 1936, remaining there as a teacher until 1948. His pupils included Sven-Olf Sandberg, Jussi Björling, and Birgit Nilsson. After returning to England he continued his private teaching career and was a vocal adviser at both Covent Garden and the Sadler's Wells operas. He recorded fairly actively at his prime, including several British ballads.