There is a long tradition of jazz artists applying their interpretive and improvisational talents to “classics” from other genres, but Brad Mehldau’s concert at the Lobero Theatre Oct. 28th was a mind blowing journey through well known songs altered almost beyond recognition. It was easy to see this master of the keys considering where to go next with each number and the results were revelatory, especially as he announced the title upon completion, often to slight gasps. Who knew all the melodic and rhythmic permutations that lay within Led Zep’s “Going to California,” the Beatles’ “The Fool on the Hill,” Dylan’s “Don’t Think Twice, It’s Alright?” Neil Young’s Neil Young’s “Don’t Let It Bring You Down” was the most recognizable, but still Mr. Mehldau coaxed new and surprising things from it. Chops aplenty combined with intellectual and emotional adventurousness to create a sonic landscape all his own, even when applied to something as seemingly structured as Wes Montgomery’s “West Coast Blues.” It’s what jazz is all about at it’s best.