"I'm originally from Kaikohe in the Far North, so the hit parade you would expect to hear in a Northland pub was what I got into."
After moving to Auckland, he "got in Celtic music in a big way" before moving to Scotland and playing traditional music there for two years.
"Then came Latin music and gypsy swing. As a musician in New Zealand trying to make a living, you never say no to a gig.
"You end up in all sorts of different bands."
Sanders, originally from England, was inspired by the movie Local Hero and took off to Ireland on his motorbike, Denham said.
"He got deeply into Irish music, and he also plays classical Indian music and Arabic stuff.
"Both of us have really broad tastes."
The Alpaca Social Club began around 11 years ago, born out of Denham and Sanders' previous four-piece outfit The Ensemble.
"That band had just finished a nationwide tour and John and I were driving north, up the highway from Taumarunui.
"We got a phone call asking if we wanted to play as a duo at the Bethells Beach Cafe that Friday. Immediately, we said 'sure, why not?'.
"The lady asked what we called ourselves, and it was a case of 'ring back in an hour'."
Denham moved from Prague, Czech Republic, to Motueka last July.
"Prior to Covid I was coming back to New Zealand for three months [a year] to tour.
"John is a third in Germany, a third in Ireland and a third in New Zealand, something like that.
"We usually get together in Europe to do a bunch of gigs, and also back here."
The two-piece had never played in the River City before, although The Ensemble performed at the Whanganui Jazz Club a couple of times in years gone by, Denham said.
Also on the bill is singer Cousin Alice, who will join the pair for a number of songs.
"Two-thirds of the time it will be just me and John, and then she will be there playing ukelele and singing for the rest of it.
"We really like her stuff. She's got her own unique style, and we love to do our thing to her music."
The Alpaca Social Club and Cousin Alice will perform at Whanganui Repertory Theatre on Thursday, March 10. The show begins at 7pm.