The Decemberists keep on experimenting

The Decemberists recently released its eighth album, "I'll Be Your Girl."

The Decemberists have staked a claim on their own corner of the modern music world.

The American indie rock band has an output that draws from the literary form of lyricism exploring the wicked side of humanity through a multitude of musical forms. Sometimes, it might take the form of an acoustic ballad, other times a jaunty country-tinged tragic tale, while others a mystical folk and prog rock epic mash-up.

That latter form has peaked in work like their nearly-9-minute seafaring drama "The Mariner's Revenge Song," or "The Tain," their 18-minute meditation on Irish mythology.

But the band — who will perform at the Massachusetts Museum of Contemporary Art at 8 p.m. Thursday, Oct. 4 — just as easily offers touching and often amusing character studies.

On their latest album, "I'll Be Your Girl," the Decemberists mix these constants with a new aspect to their sound — synthesizer right up front — and it's not something anyone expected to hear in their work. Keyboardist Jenny Conlee said it's the result of the band's constant desire to experiment and their new producer John Congleton's ability to challenge them.

"When I would be like, `I want to play the organ on this,' he would let me do that," she said. "I would play my Hammond organ, and then he would be like, `Let's try the Farfisa.' So we would try the transistor organ, which has a brighter, more attack-y sound, and then he would also be like, 'Let's try that melody line on a synthesizer.'"

Conlee said that she had already purchased a synthesizer for another project, but brought it into the studio and was excited to make use of it in a recording. Band lead guitarist Chris Funk is also a huge synthesizer fan, encouraging their use of it on the album and even getting to play some. But Conlee said sometimes she had to overcome what she already knew. For the song "Severed," she insisted on recording her part on harpsichord.

"I was really uncomfortable with the synthesizer sound, so I recorded it with harpsichord and then it just didn't have the sound — it sounds like a human being and not a machine," Conlee said. "The arpeggiator is exactly on and it has a robot feel, which I think can be quite spunky if you have the right beat behind it. My harpsichord part just didn't have the feel. I thought that was too far, but my instincts were wrong, and now I love the sound. It just took me a while to get used to it."

This is typical of the way the band works. The music is centered around the songwriting of lead vocalist and guitarist Colin Meloy, and the band's performance of these songs is built from Meloy's demos and often guided by his musical ideas through a process of playing and editing. Conlee said she and bassist Nate Query probably have the least amount of editing because Meloy doesn't play their instruments. Meloy also takes a hand in the album production.

"When it says produced by the Decemberists, it's really him," Conlee said. "He has lots of ideas. I call him compulsively creative. He can't sit still. Well, he can sit still, but he's always creating something. His mind is always going through things. That must be relaxing for him, to make things."

Meloy was forced to sit still, however, this summer in the middle of the band's tour when his vocal strain forced him and the group to cancel three shows and reschedule two, including a June 15 show at Mass MoCA. Tickets are still available for Thursday's rescheduled show in North Adams.

The band's music evokes different eras, though the music doesn't always follow that lead. As Conlee explains it, they don't want to make it so obvious and like to serve the dramatic needs of the lyrics as well as their specific place or time.

But one recurring flavor in the band's sound has been a traditional kind of English folk, to the point that their previous album was a collaboration with British singer Olivia Chaney, called "Offa Rex," to create a more pure form of the music they had been referencing for years, the result of the musical passions of Meloy and the band's drummer John Moen, who is a rabid record collector focusing on that style.

"It's a ballad style, which means many, many verses telling a story, trying to make each verse seem different. Or how to make the song grow and have a shape when it's 12 verses the same shape. You have to make it into chunks, like these three verses will have this texture, and we'll add something, and we'll take something away, and that's a fun process. So that's a unique thing," Conlee said. "'Rusalka, Rusalka / Wild Rushes' from the new record has that kind of structure."

Conlee brings the diversity of her Decemberists work to other projects. The accordion is her chosen instrument for Black Prairie, a bluegrass-styled project with three of her Decemberists bandmates, and Paper Bellow, an all-accordion quartet. Her soundtrack work has seen her embrace the Mellotron, and a synthesizer trio currently called Echo Echo Echo finds her melding her work on the latest Decemberists' record with songs by the likes of Bob Dylan and Joni Mitchell.

But the center of it all, as always, remains the Decemberists, which provides for Conlee and the other band members a unique opportunity to expand and explore while also embracing consistency. It's a balance their fans appreciate.

"You do have some things that stay in the wheelhouse that can make other things seem not so drastic," she said. "We're not losing our way, we're just experimenting."