It's hard to imagine the Boston Horns playing a sit-down concert. The seven-piece band has been burning up stages with high-energy, hard-grooving funk and soul for more than a decade and has developed a reputation for, well, burning down the house, for getting folks off their seats and onto the dance floor or into the aisles. And that's exactly what they're planning on doing next week, when the band pulls into the Port for their first local gig in years. "You'd better tie the roof down," says Horns frontman Garret Savluk. "We're going to mix it up, we're going to do our thing, we're going to blow this place up." But, as hard as it is to imagine people sitting in their seats, politely clapping like it's the US Open, while the Horns tear it up onstage, it's even more difficult to imagine Savluk up there doing it without saxophonist Henley Douglas at his side. They've been playing together for better than two decades, from the early days with The Blues Meanies, which had them backing the Del Fuegos, among others, to the years as the conceptually outrageous Heavy Metal Horns, which put them on the road with then-chart-toppers Extreme, to their work over the past ten years as the Boston Horns, opening for monster funk acts like the Tower of Power and bringing the band, and its powerhouse sound, to a headlining tour in Japan. But that's where the Horns are these days. They're still together, but the Douglas-Savluk partnership is done.