What a combination: the wry commentaries on life by Australian institution Michael Leunig matched to the witty and entertaining musical presentation of The Song Company under the direction of Roland Peelman, his final concert with the ensemble after 25 years as its artistic director.

Twelve composers from Australia and New Zealand, each supported by generous donors, were asked to create a piece to celebrate one of the 12 months of the year.

"Every year a new calendar arrives," Peelman says, "the cycle goes round and round again. Some things change, some stay the same. Let's celebrate this as a musical year. This is something that I've been planning for a long time and it's a beautiful way to say goodbye to the company. Everyone connects somehow to Leunig's work: sometimes it's dark, sometimes it's wistful, sometimes it's very funny as well; it's clever and simple and very direct, beautiful, sometimes even disturbing. His work has been in the newspapers and on our fridge doors for decades now. There's something very recognisable about his work to all Australians."

Musician Ruth McCall is one of the contributors to this unique almanac. She used to sing with The Song Company and work as an arranger for the ensemble. Her delightful and unusual arrangement of the classic Waltzing Matilda was written for them and is much performed by many choral groups, as are her arrangements of Christmas carols. "But I haven't written specifically for them for five years and am very much looking forward to this concert," she says.

Each of the composers was asked to choose a month and McCall chose October. "I wanted to choose a Leunig character and I chose the duck as the essence of Leunig. But I didn't want to put words into the duck's mouth. You could describe my piece as a vocalise." While this might seem a challenge to an a cappella ensemble the abilities of the members of the group to produce the most extraordinary non-verbal sounds will surely make this piece a highlight of the concert. It consists of "seven tiny little ducks: Duck, Thoughts, Waddle, Whimsy, Language 1, Language 2 and Wisdom," McCall explains.

Peelman says, "Ruth's setting is incredible witty – crazy and beautiful."

McCall says, "There can be a lot of melancholy and a bit of anger in Leunig's drawings but no duck died in the making of this piece! There's a happy ending. Leunig is profound. He's like Australia's conscience at times."

The concert begins, naturally, with January: Ahhh Summer! The Municipal Pool in a setting by Melbourne composer Mark Viggiani: "At the bottom of the pool you grasp the meaning of life. But weeping is impossible under water."

February brings The awfulisers set by Wellington composer Gareth Farr and March is celebrated by an extract from The Prayer Tree in a setting by Brisbane composer Robert Davidson: "Let it go. Let it out. Let it all unravel. Let it free and it can be a path on which to travel."

Lachlan Skipworth from Perth offers Leunig's tiny prayer of hope for April and Sydney composer Alice Chance, who was commissioned by Irene and Ken Hendricks to write in honour of their mothers, has created a profound and reverent piece for May.

While Katy Abbott's piece, Flying for June, and Drew Crawford's piece for July, another setting from The Prayer Tree, are serious in tone, Kate Moore, a cellist, currently resident in The Hague, finds a kindred spirit with Leunig's gruntled cellist in "this mean, disgruntled world" in her August piece.

James Wade composed the beautiful No Sooner for September, and following Ruth McCall's October Duck comes Kate Neal's whimsical setting of Refresh us with tomatoes for November.

Appropriately, Sydney composer Lyle Chan has set words from three Leunig pieces for a December finale, "and hidden in it is a version of Silent Night," Peelman says.

It's extraordinary that 12 musicians, working independently, have managed so adroitly to represent the breadth and feeling of Leunig's work.

"Leunig manages to reduce the complexity of the world to very simple things," Peelman says, "the things that as humans we grapple with; he encapsulates this."

For his farewell concert at Sydney's Independent Theatre on November 18 Peelman promises "a musical degustation with some famous Flemish entrees and a surprise main course." There will be a new piece by his friend of many years, Martin Wesley-Smith. He says that what he remembers most fondly of his 25 years at the helm of The Song Company is coming back after travelling and arriving for morning rehearsal with the six members of the ensemble. "Such a cleansing experience. I love music. It's what I love most."