At the time, she admired how Britten "brought various musical ideas together in confrontation. They were rarely subsumed and mostly remained identifiable. Here was someone who could write for anything and that's what impressed me as a student. Whatever he put down made perfect sense, whatever the ensemble, and there weren't many composers who could do that."
Britten was very much an alternative voice in an England still dominated by the mana of Vaughan Williams and the folksong tradition. His first teacher, at the age of 14, was composer Frank Bridge and, early on, he was drawn to the music of Schoenberg and Berg. He was also gay, writing many of his works for his life partner, tenor Peter Pears, a conscientious objector during the years of World War II.
"He stood out against the crowd," Grylls stresses. "Perhaps because of this he had the courage to write what mattered to him."
The 1962 War Requiem was certainly such a work, reflecting his views on the horrors and futility of war, dedicated to four young friends who had perished in the conflict. It was a deeply symbolic piece, written for the consecration of Basil Spence's newly built Coventry Cathedral, calling for three specific soloists - one English (Pears), one German (baritone Dietrich Fischer-Dieskau) and one Russian (Galina Vishnevskaya). Soviet visa problems prevented Vishnevskaya from being available for the premiere performance but she lent her thrilling presence to the 1963 recording.
Grylls points out how carefully Britten chose the texts for the piece, alternating Latin funeral rites with verses from the poet Wilfred Owen, himself a casualty of World War I.
"I can't imagine Britten wanting to write a Requiem that used only the Latin texts," Grylls adds.
There was a point in having the soprano sing in Latin. It was closer to operatic Italian than to English for the language-challenged Vishnevskaya.
However, giving these words to a choir of treble voices somehow catches the purity of the service.
"You understand the formality of the ritual," Grylls adds. "It represents the innocence of youth; in fact, this could be an anthem for doomed youth. It's very bitter and there's no surprise when the first Owen poem opens with, 'What passing-bells for those who die as cattle?"'
Owen's words are absolutely crucial to the piece, Grylls feels, and nowhere more so than in the Offertorium section.
Here, Britten cuts across the stern fugal setting of Quam olim with the tenor and baritone singing of Abraham who "slew his son, and half the seed of Europe, one by one".
Grylls pauses after quoting the Owen words, as if to take in the enormity of the image. "You can't even begin to take all of that in. My father lied about his age to join the forces at the end of the war. Today's young singers don't have the same stories or the same connection."
When she works with her choristers, she stresses the dramatic impact of Britten's Libera Me, which works through to a climax of fury, after the trebles have sung "Deliver me, O Lord, from eternal death in that awful day when the heavens and earth shall be shaken".
"In rehearsal, I mention what happened when England was bombed during the Blitz, or that raid on Dresden when fires blazed through the city and there was no place for the people to go," Grylls explains. "It's a whole story, and the work is about storytelling."
This is the second time Grylls has been involved with Britten's War Requiem, the first being in 1997 when the APO played it at the Holy Trinity Cathedral, under Michael Lloyd, with Dame Malvina Major heading the soloists. "Michael walked into the first rehearsal and said how he thought we could really make something of this," she says.
And, fatefully, the first of the two performances coincided, almost to the hour, with the funeral of Princess Diana. "It was very poignant. It was a phenomenal experience."
Wednesday's Little Britten concert is on a smaller scale, with a cheeky title that inevitably casts up images of Matt Lucas and David Walliams in different states of crossdress.
Grylls admits she has "seen some of the TV shows but doesn't watch it avidly", preferring to see the event as "a marvellous chance to bring the 76 voices of Voices NZ and the National Youth Choir together".
She will conduct Voices NZ in Sacred and Profane, a sequence of eight medieval settings that is "one of Britten's last pieces. Its premiere was directed by Peter Pears four years after his death."
A 1944 Festival Te Deum that features all the singers as well as James Tibbles on the Holy Trinity organ is quintessential Britten. "It's not a crowd-pleaser," she warns, "but he does draw you into it, right through to those last few organ chords, some pianissimo (very soft) unaccompanied voices and finally a single treble voice floating off into the distance."
Auckland Arts Festival
What: Little Britten
Where and when: Holy Trinity Cathedral, Parnell, Wednesday at 7pm
What: War Requiem
Where and when: Auckland Town Hall, Saturday March 23 at 8pm
