Mix the rootsy sounds of Arizona band Giant Sand with the ethereal flakiness of Lisa Germano and you get OP8. Tim Perry talks with the band's senior, but equal, collaborator Howe Gelb

Slush, the sublimely intense yet cathartic album released earlier this year by OP8, might have been their debut disc, but behind it are four multi-instrumentalists who've more than served their time elsewhere. Lisa Germano has recorded three albums for 4AD, and to her ethereal flakiness is added the mellow roots-meets-indie layers of Giant Sand, the cult Arizona trio with many offshoots and a discography that probably wouldn't fit on this page.

Howe Gelb, who formed Giant Sand way back in 1981, is in enthusiastic form on the line from Munich, declaring that "some lush and wonderful things have been happening on this tour". When asked what made this collaboration such a thrill, Gelb required, "Well it's the eighth one. The Other Project 8." So the name isn't a druggy reference? "Well hopefully it's that as well. The OP8 album is a drug and the first taste is free. Hopefully you'll become addicted to the soundscape and it will be something you'll need on occasions.

"The overall principle behind OP8 is to come together equally. Whatever way you slice it with Giant Sand, I've been there forever and you get that unavoidable seniority thing. I was really ready for things to even up. Then Lisa came down to Tucson to work with us on one of her songs but that fell through, so we thought maybe this is supposed to be OP8. Maybe we are supposed to have a fourth person and not always the same fourth person."

Indeed Gelb has made formal contact with Clint Eastwood, of all people, to be the next OP8 collaborator, though, it's easy to imagine Eastwood's gruff tones meshing into the desert strums of Gelb and company while covering territory from spaghetti western twangs to jazzy Latino borderland jams.

Meanwhile this tour has seen some new departures. "We wrote a setlist for the first time in 20 years, or however long it's been. Then somebody stole it. The point is that we wrote it and we're proud of that. But the idea is tickling us that we're actually pretty much playing the record," claims Gelb.

Another first came in Sweden when they were asked to lip-synch while crawling through dry ice on primetime TV. Their slot got pulled as the producer thought they were on drugs. A puzzled Gelb reckoned, "Hey it was just OP8. It was just our natural droop of the eye. Our weird little stance."

With so many possibilities within OP8, it's appropriate that support comes from within their ranks. The country-tinged Calexico are the OP8 rhythm section of Joey Burns and John Convertino along with singer Tasha Bundy. To quote Howe Gelb, it should be a lush and wonderful night.

OP8 featuring Lisa Germano, Calexico: Dingwalls, NW1, 16 Oct

OP8's 'Slush' (V2) and Calexico's 'Spoke' (Quarterstick) are both available now