Change comes very easy to viperHouse. As a nine-piece ensemble that has made a name for themselves in both jazz circles and jam-band festivals, the Vermont-based band’s ability to morph any song into an entirely new aural experience comes as easily as walking and chewing gum.

But for anyone who has been lucky enough to catch viperHouse at any of their increasingly crowded (and sold-out) appearances at Lancaster’s Historic Blue Star over the past two years, the next viperHouse show will be an eye-opener. The band, which annually performs more than 100 shows, recently announced the departure of three members — Heloise Williams (vocalist), Brian Boyes (trumpet), PJ Davidian (percussion) — and the addition of Zack Tennyson on tenor sax. "We will be a different band," explains Michael Chorney, who started the band in 1995, "but it seemed like a good time to open the door for everyone. viperHouse is at a place where the next step is right in front of us and it should only be made if we are making music for the sake of music and letting other things fall in after that. Heloise has really focused on songwriting and she has shown me some great songs that viperHouse could still play, but her songs are crying out for a different musical world. So we mutually agreed that now was a good time for her to explore songwriting."

While Williams initially joined viperHouse as a flutist, her vocal abilities propelled her to a focal point within the band. With her departure, viperHouse will be returning to their very origins. Chorney dreamed up viperHouse while traveling in Europe. He modeled the band on old jazz orchestras like Duke Ellington and Fletcher Henderson’s traveling bands, and more modern groups like Sun Ra and his Arkestra. "I think those bands all basically played the groove music of their time, however, they didn’t compromise the integrity of the music," says Chorney. "They played challenging material, but underneath it all was basically dance music. In their time it was swing, and in our time it’s funk and hip-hop."

With their funky side proudly on display, viperHouse has become a huge draw at both jazz festivals and multi-day festivals that feature bands emulating Phish and The Grateful Dead. While Chorney isn’t sure which label best fits the band, calling viperHouse a jazz-funk band is fine with him. "The characterization doesn’t bother me because at our live shows, people dance their butts off," says Chorney, who divides his time between baritone and alto saxophones. "There are people who are there to boogie and then interspersed through the crowd on the sides and in the back are the people who are just sitting there listening intently. In our humble way, we are trying to carve out our own niche in this jazz-funk genre that is emerging in groups like Medeski, Martin, and Wood. From the start, we have gotten up there and proclaimed this our take on the genre."

And a startling take it is. On their newest release, Lap Hen (Magic Hat Music/www.magichatmusic.com), viperHouse glides like a well-oiled machine across stellar original numbers and beautiful covers by Duke Ellington and Sun Ra. While the horns jump off Lap Hen (recorded live at two shows in Brattleboro, Vermont), the incessant groove created by drummer Phil Carr, bassist Rob Morse and keyboardist Ray Paczkowski brings viperHouse to life. Rounding out viperHouse’s sound is trombonist Dan Mallach and violinist Karen Quinn.

While viperHouse regularly features some vocal tracks in their live shows, the new lineup will see a return to more instrumental number with group vocals worked in as needed. And while Chorney serves as bandleader, he is one of many songwriters in the group. When the band started out Chorney did the lion’s share of the writing because it was more efficient when working with such a large band. "The best thing about viperHouse is the talent with every player in the band," says Chorney. "Everyone can play from charts or handle total improvisation. In the beginning, I would chart all the parts for everyone to make the best use of rehearsal time. A lot of the songs still changed, but now, we have multiple writers within the band and numerous ideas coming to life. With the smaller group, we will probably continue to stretch the writing and let the group build the original songs."