From their first gig at an Earth Day festival and their early days on the traveling H.O.R.D.E. Festival to their current status as the hardest-touring summer act since the Grateful Dead — not to mention frontman Dave Matthews’ status as the fourth performing board member of Farm Aid — the Dave Matthews Band is practically synonymous with festivals and outdoor concerts. A hero of the jam band nation, Matthews and his jazz/rock fusion outfit, formed in Charlottesville, Va., can be counted on not to stick to a formula. You want samplings from this June’s, Big Whiskey and the Groogrux King? Odds are good. You want “Tripping Billies,” “Crash Into Me,” “What Would You Say,” “Ants Marching” or his feverish cover of “All Along the Watchtower”? You might get lucky, but keep an open mind, because this band’s got a vast repertoire and isn’t given to delivering rote versions of the same old hits. Matthews, bassist Stefan Lessard, violinist Boyd Tinsley and drummer Carter Beauford, along with sax player Jeff Coffin of Béla Fleck’s Flecktones (replacing LeRoi “Groogrux” Moore, who died last year from injuries sustained in an ATV accident) and trumpeter Rashawn Ross, are given to flights of sonic fancy marked by the kind of tightness that only bands on a telepathic wavelength can achieve night after night.