One Grass + Two Grass = Bluegrass + Newgrass. There are certainly plenty more sums, factors, outcomes and equivalents in the equation, but one thing is certain, almost scientific: One Grass Two Grass’ style of reinvented and revived modern bluegrass sounds usually equate to a hip-swayin, barn-stormin’ rip roarin’ good time! The SF Bay band has steadily gained an active fan base since its inception, largely as a result of active touring, festival appearances and down-home word-of-mouth generosity.