Jerks of Grass is a bluegrass band, which means that at least one of the musicians has a banjo. It also means that we’re treated to a particular kind of talent: the kind that feels no shame in letting you know how good it is. Bluegrass is generous. When these musicians push their instruments as far as they’ll go they don’t hide it. There’s no gentlemanly veneer of modesty or concealment. When the banjo player goes so sharp and high in “Twin Peaks” that the instrument is gobbling with effort he lets us hear every cluck of tension in the string, and when he dips low in “Foggy Mountain Special” we get every hammocky boing. We’re here to share a mutual joy in their expertise. This album, the group’s first after more than a decade of live performance, starts happy and stays happy for much of its length, slowing down for one or two songs about women who done the singer wrong. Otherwise it’s plucky as a shot of coffee.