Although accomplished as a pianist and involved in prestigious ensembles, this British classical musician's responsibilities went well beyond simply caressing the keyboard. The credits for the premieres of composer Benjamin Britten's Curlew River, based on a Japanese Noh theatre play, read like this, after all: "Music under the direction of Benjamin Britten and Viola Tunnard." The credits were exactly the same for Britten's The Burning Fiery Furnace. Tunnard was this composer's right hand, assisting not only in musical arrangements and conducting, but also acting as a kind of "répétiteur," in the words of baritone John Shirley-Quirk, who worked on several Britten premieres. Tunnard would bring personal instructions from the composer to rehearsals, allowing Britten to keep himself at more than an arm's length. Britten and Tunnard often share credits, sometimes quite unusual ones. On the Decca recording of the Percy Grainger set of Folk Song Settings, the tuned hammer-string players are Benjamin Britten and Viola Tunnard. Tuned hammer-strings? Britten and Tunnard were playing the strings inside the piano, in imitation of the sound of a hammered dulcimer from the Färoe Islands. Tunnard had plenty of experience with the likes of Monteverdi, but many of her best performances involved the decidedly more modernistic efforts of Britten and his contemporaries, or the impressionistic Debussy. She was also involved in the music of Ralph Vaughan Williams, and recorded Linden Lea with Shirley-Quirk. The pianist was also active as an arranger. In 1942, she collaborated with choreographer Molly Lake on a dance piece for the Ballet Guild involving Tunnard's arrangements of the music of Offenbach. She returned to this composer's music much later in her career as well. The stage production Not in Front of the Waiter or Under the Aspidistra, again based on the music of Offenbach, with orchestration by Vilem Tausky, was presented as a Gala Midnight Matinee by Sadler's Wells in 1963. This time around, the multi-talented Tunnard wrote lyrics, with book and adaptation by Colin Graham.
Her jobs as a piano accompanist were quite varied, ranging from the Vienna Boys Choir to the sophisticated British performer Joyce Grenfell, with whom she spent several years touring military bases during World War II. A Viola Tunnard Memorial scholarship was established for study at the Britten-Pears School for Advanced Musical Training. Winners of the scholarship include the soprano Sarah Jane Whyte.