“It’s impossible to categorize this music, what would you call it?” the friend who accompanied me to see The Mickey Hart Band on Thursday night in Jerusalem kept saying.And there wasn’t really any answer. Like his mother ship The Grateful Dead – the legendary free-form jam band that could veer from country and blues to guitar freakouts and atonal space jams within the same set – the 69-year-old Hart brought a sense of adventure and unpredictable wonder to the two-hour-plus show while masterminding the proceeding surrounded by 360 degrees of percussion instruments and electronic devices.The setting couldn’t have been more perfect – the Mount Scopus Amphitheater under the clear skies with a near full moon and glimpses of the Mount of Olives behind the band. The audience at the amphitheater, seemingly filled to only about 70% capacity, consisted of many English-speaking Israelis of every ilk, from hitech yuppie Dead fans to grizzled Carlebach veterans to young yeshiva students doing the Deadhead spin with tzitzit flying, as well as a mixture Hebrew-speaking fans.More like an orchestra than a band, the musicians relied on interaction, telepathy and maestro Hart to provide direction. In between his pounding drum fills, he offered hand signals, eyebrow gestures and waves of his arms to nudge, encourage and prompt his fellow players to edge closer to the musical unknown.The show was divided, like the Dead’s concerts, into two sets – something Hart announced was special on the band’s current tour to match the uniqueness of the locale. But instead of individual songs, the music blended together, transitioned from piece to piece with jams, delicate harmonics or huge electronic noises. Before the first song, Hart said, “I guess let’s start at the beginning,” and as “Ghost Rider” from the band’s new album Superorganism music rose from nothing to pounding intensity, it did feel sort of like creation in motion.Of course, the vibe immediately changed with a rousing version of the Dead favorites “China Cat Sunflower” and “I Know You Rider,” performed with verve and original touches by the band. Guitarist Gawain Matthews, while no Jerry Garcia, was not afraid to step out of the Dead guitar hero’s well-worn footsteps to propel the songs into new territory. The real revelation of the band, though, was vocalist Crystal Monee Hall from the Tony Award-winning musical RENT. The crowd-pleasing singer brought an element of r&b, soul and gospel to the music that the Dead never had.Hart seemed to be having a grand time, whether playing off fellow percussionist Sikiru Adepoju across the stage on talking drums, mugging with Hall, or manning his battery of instruments. The highlights of the show were, of course the nicely placed Dead tunes like “Scarlet Begonias,” “Fire on the Mountain” and “Playing in the Band.”As much fun as it was to watch the band’s interaction and the amazing level of musicianship, the Hart Band material was clearly no match for old favorites. But unlike his former bandmates like Bob Weir and Phil Lesh, who basically tour rehashing the Dead’s material, Hart should be applauded for still creating new music with young, enthusiastic musicians and not solely relying on the Dead’s good name.And applauded he was after two hours of seamless, often mesmerizing music. As a reward, Hart offered as an encore a simply angelic version of the Dead classic “Stella Blue.” Brought down to an even slower tempo than the Dead’s version and mournfully sung by Hall, the song had the crowd silenced and swaying, as if in prayer. Right around then, the fact that the Mickey Hart Band was performing at the Sacred Music Festival started to make a lot of sense.