The Idea of North sing ballads in Groove Sessions at The Street Theatre

Is it the total exposure of the voice that makes a cappella singing so exciting to hear?

The Idea of North, the quartet founded in Canberra in 1993, has attracted audiences across Australia and internationally and they are heading back here for two concerts at The Street Theatre, one of their favourite venues. They will be promoting their latest album, Ballads, the idea of which sprang from the success of their Ballads by Candlelight show at the Adelaide Fringe Festival seven years ago.

Nick Begbie, the group's tenor, says, "Yes, we love to sing ballads," and Naomi Crellin, alto, adds: "I think ballads are the most chock-full of emotion and they're the ones that our fans request the most. When we did a tour of Australia where we gave out a song menu and let our fans choose which songs we'd sing they just kept requesting ballads – we actually had to try to encourage them to choose some other songs but they did prefer the heart-wrenchers."

Begbie says he thinks the thing singers have over instrumentalists is the lyrics, which send a message to the audience. "Ballads give people the time to dwell on the meaning of the lyrics. While we really do enjoy singing up-tempo music we're just revelling in the current project of recording an all-ballad album. It's been wonderfully enriching,"

Crellin adds:" It's sort of two things in one with the ballad: the richness of both the music and the story. Up-tempo lyrics are not usually as deep or involved."

Of course, The Idea of North don't specialise exclusively in ballads. Their repertoire ranges from a comedic take-off of a Gregorian chant to a comedy piece based on a Bach fugue and German folk songs from early 19th century, through to jazz and up-tempo pieces.

You might think, listening to some of the tracks on this new album, that the group has sneaked in a range of instrumentalists. No. What you're hearing is the incredible voice of Kaichiro Kitamura, Japanese vocal percussionist extraordinaire, mimicking an amazing range of instruments to accompany the voices of the four members of the ensemble.

"Kai's touring with us," Begbie says. "He's a remarkable musician who started singing and doing vocal percussion when he was really young. Then he decided that he wanted to learn about what he was doing so he studied jazz drumming and became an actual drummer. Then, after about six years he went back to vocal percussion and he's now one of the world's only specialists in jazz vocal percussion."

Begbie says you can't forget the experience of hearing Kai perform because it's so unbelievable. He emulates a drum kit: snare drums, high hats, cymbals, kick drums, tongs, shakers of all sorts and woodblocks. "Kai might be doing woodblocks while he's playing a bossa nova drum pattern. There's no overdubbing – just the one track. It's amazing and it suits our style really well because one of our favourite types of music is jazz so it's very special to have someone who is so incredibly physical and knowledgeable about the funk and jazz genres to be doing the percussion for us."

Several other musicians collaborate on the album but Kitamura is the only additional touring member for Idea of North's current tour.

Track five is Sarah McLachlan's song Angel in an arrangement by Crellin with Joy Hague as an additional alto. Begbie says: "We recorded this song a little while ago but it's been so popular that we put it on this ballad album."

Track six is an arrangement of My One and Only Love, the song by Guy Wood and Robert Mellin that was made famous by Frank Sinatra. The five-part arrangement has been made by tenor Ed Fairlie, "a guy from Melbourne who sang with us on our Christmas tour last year when we sang as a quintet on that fun tour," Begbie says.

Australian jazz singer Kristin Berardi joins the ensemble as the guest lead in her own composition Ode to Oli on track nine.

Dance Medley gives Begbie the opportunity to not only sing but to show his talent in a vocal trumpet accompaniment.

Begbie names the album's first track, "a very imaginative arrangement by Naomi of Cold Chisel's Flame Trees", as his favourite on the album. But there are numbers by Sting, the Bee Gees and finally, Lullabye (Goodnight My Angel) by Billy Joel . So hard to choose ...

The group love The Street Theatre as a performance venue. "There are no bad seats in The Street," Crellin says. "The audience can feel very much a part of the action."

"And we love performing in Canberra, where it all began," Begbie says.