Van Morrison,”Three Chords and the Truth” (Exile/Caroline International)-The irascible Ulsterman continues to mine a rich vein of creativity as he unveils his sixth album in just four years. The Righteous Brothers’ Bill Medley and veteran jazz guitarist Jay Berliner are both on hand to underpin the great man’s efforts, the latter resuming an artistic collaboration which began half a century ago when he played on Van’s classic 1968 album,”Astral Weeks.” The finished product provides a typically absorbing vehicle for Morrison’s meditative musings, with “March Winds in February,” “Nobody in Charge” and “Days Gone By” emerging as three of the musical highlights.