The type of accordion you play may affect your chances of getting into heaven. When Basque musician Joseba Tapia was six years old and showed interest in playing traditional dance tunes on the squeezebox, his family and the local priest became nervous about his choice of instrument.

"An uncle made me a present of a plastic accordion, and I was able to play a fandango with it," recalls Tapia, on the line from his home near San Sebastián, in northern Spain's autonomous Basque region. "Everybody thought, 'This little guy has something in his blood.' But they didn't want me to take up the diatonic accordion, as the instrument was considered bad in that society. The Catholic Church had strong objections because it led to dancing, which of course led to other things. It was given the name el fuelle del infierno [the bellows of hell]."

Tapia–who leads the quartet Tapia eta Leturia–was persuaded to take up the spiritually safer chromatic, or piano, accordion instead, and for many years he dutifully played mainly classical music. But he longed to get his hands on the diabolic box, which he heard at fiestas in small towns and villages in his mountainous homeland. When Tapia was in his mid-teens his father relented, and an uncle taught him trikitixa. The Basque word refers not only to the diatonic accordion itself (which is also used in Cajun music), but to a particular type of folk dance and the tunes created for it.

"Trikitixa is just one kind of traditional music in our culture," explains Tapia, speaking in Spanish. "We play two rhythms, basically–the fandango in 3/4 time, and the arin-arin in 2/4 time."

In the late '70s, Tapia gained local fame as a young trikitixa player whose fingers flew over the keys with blistering speed and accuracy. He teamed up with virtuosic pandeiro (tambourine) player Xavier Leturia in 1984, and together they drove dancers into Dionysian frenzies while somehow avoiding excommunication. "At first we were playing only in Guipúzcoa, the province I come from, and rural towns in the highlands. But soon we were doing concerts, weddings, and parties all over the Basque country."

The pair didn't limit themselves to traditional folk. Their 1995 self-titled disc draws on reggae, rap, punk, and the radical rock scene in their homeland. Tapia has launched a solo career that includes performing modern Québécois songs translated into Basque, and an album that features Basque songs, many of them unpublished, from the Spanish Civil War era.

When Tapia eta Leturia come to the Vancouver Folk Music Festival this weekend, however, they'll be playing the old-style trikitixa–with a fresh twist. Despite the name the duo is now a quartet, with the addition of Arkaitz Miner on fiddle and mandolin and Jexux Aranburu on keyboards.

"We were the first group to expand the traditional trikitixa duo of accordion and tambourine, and it gives our sound much more depth and variety of textures and harmonies. We play the dance music I grew up with, though also some new compositions. In such ways we keep pushing forward the music we love."

Tapia eta Leturia plays the Vancouver Folk Music Festival on Saturday (July 14).