When local band Obsidian’s Dream performs at a concert, the event becomes much more than a gig.

It becomes much like their song “Family Vacation.”

Four of the band’s five members have children, and when the band performs, the various families pile into three Volkswagen buses to watch.

Duff says the thing that really makes Obsidian’s Dream different from most bands, however, is its ability to improvise.

“The structures we use aren’t very well defined,” says Eric “Bert” Carlson, the bass guitarist. “Within the songs we play, there’s a lot of room for maneuvering. At any given point in any particular song, any one of us may be ad-libbing.”

Duff says the band’s practice sessions often include “impromptu jams” that can consist of two or three different songs.

“We just feed off each other’s inspiration,” he says.

“There’s no real set structure to how we write.”

Carlson says although the band performs a lot of impromptu music, it is generally not noticeable to the audience.

“As a whole, [our music] doesn’t sound impromptu, but throughout the night, everyone’s going out on a limb at some point,” Carlson says.

Much like its songs, Obsidian’s Dream formed “on the fly” almost a year ago from the ashes of other bands like Silas Marner. Four of the band’s members first played together at a Halloween party in 2003.

The band was completed in February of last year when Carlson joined as bassist. The band members’ styles and music tastes vary widely, including jazz, reggae, rock and heavy metal.

Mike Larrew, the band’s guitarist, says he likes the spontaneous nature of Obsidian’s Dream.

“It’s a lot more fun than being so rigid and being so particular about it,” he says.

Larrew says the only way to classify the band is as alternative, but not today’s typical catchphrase of alternative.

“To me, alternative is something nobody else is doing,” he says. “And that’s what we’re doing. But we’re not alternative in the sense of grunge.”

Larrew says the band performed everything from bluegrass to “Jesus Christ Superstar” at its last show at the Bali Satay House on Saturday.

“We’ve got such a vast range of music that anybody can listen to us and not hate us,” Duff says.

Larrew says one thing Obsidian’s Dream tries to avoid playing is cover songs.

“When you go out and play a lot of cover songs, you’re trying to basically bite someone else’s emotion,” he says.

“We go out there and play our own stuff, and then play it on the fly on top of that.”

Although the band has only been together a year, it has already performed almost 40 live shows.

Duff says the band is taking the next month off to record more radio-friendly versions of its songs.

Carlson says although the band will try to format some of its songs for radio, that’s not its main goal.

“We just love to play so much, and that’s why we have these 40-minute songs,” he says.