It used to be that the phrase "jam band" meant something fairly specific: a group that drew almost exclusively from the Grateful Dead, the blues, or both. These days, though, all kinds of bands "jam," and as such, the genre has found room for everything from worldbeat to jazz to art rock.
Just how wide a range the term accommodates is evident in the Holiday Jam Sunday night at Bohager's. Topping the bill is I Mother Earth, an ensemble whose sound could be described as something both Peter Gabriel and Dave Matthews might like; also onhand is Orange 9mm, a group that manages to evoke elements of hardcore and techno without really sounding like either. Expanding Man rounds out the bill.