If you're feeling a bit down, there's no better cure than watching the video for I Wish That I Could See You Soon, the new single from cult folk-pop siblings Herman Dune.

There are puppet angels playing little trumpets. There are bubbles and bean bags and bouncing foam letters. There are genuinely cute kids forming percussionplaying crocodiles.

And there is David-Ivar Herman Dune, a living Quentin Blake illustration with his sweet grin, erratic ginger beard and long skinny legs, singing about long-distance love and doing bendy dancing while wearing a fluffy pink bear-head.

"My friend Kimya Dawson from the Moldy Peaches gave the bear head to me," he explains. "I have a new one now, a brown one, which goes better with my beard. But I thought the kids would like the pink one."

And did they?

"They liked making fun of me, so I guess they liked it."

Playing the beautiful Old Ship Hotel Ballroom tomorrow as part of Melting Vinyl's 10th birthday celebrations, Herman Dune were formed in 2000 by brothers Andre and David, who are Swedish and Jewish but were brought up in Paris.

They shared guitar, vocal and songwriting duties, with the Swiss percussionist Neman later joining them and changing his name to Herman Dune by deed poll.

Giant, their brilliant fifth album, was recorded in a studio on Mount Snowdon (or "Snow-down", as David insists on pronouncing it) because that was the only place they could find vintage Fifties microphones.

It is full of gently affecting songs about love thwarted by geography.

"Maybe almost all of them were written on the train from Manhattan to Coney Island," David tells me of the songs he contributed. "It's a very long train. I always use more or less the same chords, like, for every song, so I didn't know the single was going to sound a little more like, maybe, a happy tune sort of thing." Before Herman Dune, David wrote comic books about a man with a wolf's head.

One adventure was a remake of Dostoyevsky's The Double. Another hinged on the discovery of a magic ram that gave the wolf-headed guy the power to "be a good artist". He has just finished a commercial art book, and drew the cover art for Giant.

"Honestly I think the main reason we called the album Giant was because I so wanted to draw a giant," he confesses.

"And the little guys next to the giant - they're the band in, like, fake fur scuba suits."

Shortly after finishing Giant, Andre, the eldest Herman Dune, announced he was leaving the band to pursue his solo work. "He was like, I don't think I'll have time enough for the band any more'," says David. "It was kind of scary because we've always played together, but the best thing to do was just play. It's gonna be a year from now soon, and I haven't had too many complaints."

Although the band has lost a brother, they've gained a sister. Lisa Li-Lund, David's younger sister, is an artist in her own right with an album, Li-Lund Ran Away, out on East Sussex's Smoking Gun Records. But she is now providing vocal support with girl-group The Woo Woos.

"It's far better than any female group I've ever heard," writes David on the band's MySpace site, where his postings tend to take the form of idiosyncratic poetry.

" Except maybe the Dixie Cups. They are so good. It's so fulfilling to hear them sing our songs."

  • Starts 7.30pm, tickets £10.50/£12.50 from Rounder (01273 325440) and Resident (01273 606312).