"I see everyone as replaceable," Omar Rodriguez-Lopez says of his band, The Mars Volta.

The guitarist, songwriter, producer and autocrat of the Mexico-based progressive rock band believes there's no place for democracy when it comes to music.

Aside from singer Cedric Bixler-Zavala, with whom Rodriguez-Lopez formed the band in 2001, The Mars Volta has no permanent members, only "consistent" ones.

"Even with the best intentions of making a democratic system, democracy doesn't exist and doesn't belong in art ... What I learned after my last band is there's no reason to try and disguise that and there's no reason to pretend that it's anything else, and things will go by a lot smoother and quicker if you're clear about it from the beginning."

The "last band" he refers to is American post-hardcore outfit At the Drive-In, which broke up in 2001 after artistic differences.

Rodriguez-Lopez and Bixler-Zavala went on to start The Mars Volta; At the Drive-In's other members, Jim Ward, Paul Hinojos and Tony Hajjar, started alternative rock band Sparta.

Democracy led to At the Drive-In's demise, Rodriguez-Lopez says.

"We pretended to be a democracy but the other three guys in the band had real great resentment against myself and Cedric because when things came down to a vote, if we wanted something to happen, it happened, and if we didn't, it didn't and that's the way it was."

Years went by before Rodriguez-Lopez spoke to the members of Sparta, and although Bixler-Zavala has raised the possibility of an At the Drive-In reunion, Rodriguez-Lopez says it's not going to happen.

"It was weird at the beginning because it's like an ex-girlfriend. I broke up the old band, I don't think they wanted to see much of me for a good amount of years because they didn't want that relationship to end. When you leave a a woman or if a woman leaves you, whoever does the leaving doesn't have much interest in seeing what the other person's doing, you left for a reason."

But the autocratic Rodriguez-Lopez warms up when conversation turns to The Big Day Out, which will bring The Mars Volta back to New Zealand on January 15.

"It's probably one of the best festivals around," he says.

"It's hard to explain unless you play a lot of festivals and tour a lot and sort of get into the monotony of festival shows, and Big Day Out has something that money can't buy, it has a vibe, it has a thing to it, it has a feeling to it and it's something that you either have it or you don't. You can throw all the money in the world at a festival and it's the one essence you can't buy. It either happens because of the creators and environments are going out together or it doesn't, and very few festivals actually have that."

This time around, The Mars Volta will make it onto the main stage at the one-day festival in Auckland (they played a small stage in 2006), echoing the band's mainstream appeal -- this year's Octahedron album reached number 12 on the US music charts; their previous album, 2008's The Bedlam in Goliath, reached number 3.

That success has surprised Rodriguez-Lopez, who says it's "a joke" that he gets to make music for a living.

"I'm not a musician, I've just gotten by imitating once, and I imagine I can easily imitate something else and get by," he says.

"I don't wanna be 48 and in tight pants on stage playing rock n roll music, there's nothing appealing about that to me, that's not my life."

With 14 years left before he's too old for tight pants, Rodriguez-Lopez has plenty of time left to change his mind about the band's direction.

"The future of the band, I don't know. I'll have to get there. I'm in the present right now," he says.

"I just need some sort of change, need some sort of radical change in sound and in what we're doing and whatever it takes to get there, that's the future of the band."

*The Mars Volta play The Big Day Out at Auckland's Mt Smart Stadium on January 15.