Twenty-five years ago Helen Swan gathered 12 young singers in her lounge room to enthuse them about the sound of blended voices in a cappella song. From this small beginning the group has won international awards, produced four albums on CD and collaborated with international artists.

Essentially though, The Resonants are Canberra-based, and one of their highlights was taking part in the celebration of Canberra's Centenary in 2013 in the premiere of Andrew Schultz's Symphony No. 3 – Century. They are also proud to contribute to the Canberra community and over the years have helped raise funds for the 2003 Canberra Bushfire Appeal, for the Red Cross and for The Canberra Hospital.

To celebrate 25 years of performance the choir decided to commission a new choral work and in keeping with the philosophy of encouragement and support for young, emerging Canberra musicians, Kirsten Duncan, long-time Resonants singer and the choir's project manager, was given the task of finding the right composer, someone who could fit the words of her own poem, Resonance, to music.

Swan says, "Kirsten did all the hard work exploring composers."

Their choice of Sally Greenaway came about after Swan and Duncan attended a concert celebrating Anzac Day which featured music by female composers.

Duncan says, "Sally's piece was an instrumental piece but we liked it so much that it sold us on asking her to compose a piece for us. Sally is very passionate about what she does – as I am. She told me that her creative process started from listening to Resonant recordings and from the list of pieces we had given her as examples of music we like, then exploring the text line by line to see how the music could create the expression of the words: create a world around that with lots of colour, staggered entries, fullness and resolution, space and richness."

Duncan explains that her experience of singing in a group led her to feel the connection with the other singers and to the sense that an individual voice, even though it may be nothing special, when blended with other voices "becomes something magical, a unified whole, a beautiful creation. My poem describes the individual emotional journey, the physiological process and the broader societal impacts of discovering group singing", and this is the very essence of what The Resonants choir is all about.

Greenaway describes her composing process as "a little note [that] starts as a spark and goes on an amazing journey, then comes to rest in a moment of pure harmony," and Duncan says, "I watched my original poem transform into a beautiful piece of music. Sally told me that this was the best thing she had ever written of over 60 works."

While Resonance, which will be performed immediately after interval, will beat as the heart of this concert, the inspiration for the program was, according to Swan, "our favourite pieces over the 25 years of the group's existence".

The concert will start with Viva la musica by the Hungarian composer Ivan Erod, a musician much influenced by his compatriots Bela Bartok and Zoltan Kodaly. Then the audience will travel back in time to Music divine, a piece by Thomas Tomkins, a prominent member of the English Madrigal School in the late Tudor and early Stuart period. A 1601 piece by John Bennet, All creatures now are merry-minded, will follow and after that a choral setting by American conductor and composer David Dickau of If Music be the Food of Love – a quote, of course, from Shakespeare's Twelfth Night. Northern Lights is a piece by contemporary Norwegian composer Ola Gjeilo and the first half of the concert will conclude with Debussy's Trois Chansons de Charles D'Orleans.

Swan says, "The only other Australian piece besides Sally's on our program is The Island by Canberra musician Louise Underwood."

The rest of the program is from contemporary (or in the case of American Jester Hairston, composer of much film music and of the popular Christmas carol Mary's Boy Child, almost contemporary – he died in 2000 at the age of 98) composers and arrangers: Butterfly by Mia Makaroff, The Owl and the Pussycat by John Rutter, A Boy and a Girl by Eric Whitacre.

To finish there will be a piece, Africa, arranged by someone who learnt his craft as a baritone with the famous King's Singers, Philip Lawson.