It’s tricky to pinpoint exactly what it is that Railroad Earth does, since they mix mostly acoustic sounds with some electric, bluegrass and blues with rock, and tight songs with improv jamming. But whatever it is they do, it’s working. Members of the band were tapped by Grateful Dead bassist Phil Lesh to play some shows with his band in 2004, and Railroad Earth’s star has continued to rise ever since. They played at the smaller Antone’s the last time they came through Austin, and La Zona Rosa’s larger space is pretty jammed on a Friday night.

Guitarist/singer Todd Scheaffer and violinist Tim Carbone seem to be the ringleaders, but the sextet’s entire lineup contributes to a sonic tapestry where the whole often rises to a greater level then the parts. Some of the members’ grey hair gives away the fact that these are seasoned musicians, but there’s vitality in the music that appeals to music fans of all ages judging by the crowd.

“Been Down This Road” from 2008’s Amen Corner LP is an early highlight with its deep vibe of folky yet bluesy catharsis. The violin of Carbone and the banjo of multi-instrumentalist Andy Goessling blend beautifully with the mandolin from John Skehan. “Right in Tune”, from the same album, is another folky winner about finding that special someone. There’s an uplifting vibe in the tune that is contagious, which earns a big cheer at the end.

The band also has a strong new eponymous album that has just been released. It shows the group continuing to hone their craft, while also exploring some fresh new directions. A clear standout track is “Black Elk Speaks”, which the band drops toward the end of the first set. It’s one of the heaviest songs Railroad Earth has ever recorded, and the tribute to the legendary Sioux holy man sounds like an instant classic. The band shows great skill with the bluesy riffs and heavy groove, while Sheaffer delivers some of his most soulful vocals. Bassist Andrew Altman and drummer Carey Harmon are at their best here. The band then rides the elevated energy level into “Long Way To Go” to close the set, which receives instant appreciation from the crowd. Skehan’s slick mandolin riffs set the course and the rest of the band follows for a great jam that has the crowd hooting, hollering and getting down.

The band comes out swinging after the set break, launching into a clear fan favorite with “Mighty Wind”. The blend of mandolin, banjo, guitar and violin blend into a downright intoxicating flavor, with all the instruments gelling superbly. It’s amazing how some crisp banjo playing can elevate a rock groove. The banjo/violin dueling between Goessling and Carbone is stellar. Then there’s a great mandolin solo, followed by a smoking violin solo from Carbone. The mighty violinist looks like he’s got some hobbit heritage when you view him jamming up close, totally engulfed in the song. It would be no surprise if Carbone’s lineage did trace back to the Baggins clan, for Bilbo Baggins was indeed known as a skilled songwriter. It’s also not hard to imagine a lot of big mandolin, banjo and fiddle jams going down back in the Shire.

It’s only too bad that La Zona Rosa does not employ a fan-friendly security policy like many venues in Austin. There’s a tall security guard who may as well be from Mordor at the edge of the crowd, watching like a hawk for anyone who might light up a chocolate cigarette, ready to give them a hard time. But it seems nothing will stop this fun-loving crowd from having a good time. The new “Jupiter and the 119” is another highlight, an upbeat melodic number that keeps things grooving and which features some more tight banjo/mandolin/violin action.

“Dance Around Molly>Dandelion Wine” sees the band throwing down a serious old school hoe-down jam, led by Carbone’s ace violin work over an up-tempo beat. Then Goessling comes in with lightning quick banjo runs, and the band is soon off to the races while the crowd dances up a storm. There’s an old world flavor that is downright refreshing to hear in 2010. Perennial favorite “Warhead Boogie” provides yet another peak, with its satirical lyrics about the modern war machine and its epic composition that starts off slow and steadily builds into a monster jam.

The band plays right up until One AM and then comes back with a great encore of The Band’s “Acadian Driftwood”. It’s an appropriate nod, since Railroad Earth’s blend of classic musical styles is heavily influenced by the legendary group. It’s a stellar rendition with Carbone, Sheaffer and drummer Harmon all singing different verses and then blending together on superb harmonies for the chorus. Goessling adds some flute that fits just right, and it’s a perfect cover. Then the band revs it up for one more dance jam with the bluegrass-tinged “Bringing My Baby Back Home”. The crowd-pleasing finish seems to indicate that the band’s audience will continue to grow with each return visit to town.