Jam bands, with their fifteen-minute songs and four-hour concerts, tempt fans with the promise of endless music, an eternity spent twirling to cosmic jazz and out-there guitar noodling. So when such a group goes on hiatus, the silence is all the more deafening. Phish, every hippie's favorite nonfrozen Vermont export, swam away from the mainstream a few months ago, declaring itself on indefinite leave from its trademark endless touring. Einstein Electric emerged from its own two-year hibernation -- coincidentally, the Lawrence band claims -- soon after Phish made its announcement, and Einstein Electric's return should bring new shine to local crazy diamonds bummed by Phish's disappearance. Fervent Einstein Electric fans once posted Web proclamations declaring the group Phish's heir apparent, but because the business of Internet prophecy makes astrology seem like a science worthy of the group's genius namesake, few took notice. However, the jam-band throne is now vacant, and Einstein Electric, now featuring former Space Pocket bassist Chris Handley alongside original members (guitarist Brian Baggett, keyboardist Ben Singer and drummer Matt Miner), seems uniquely suited to ascend to royalty status. Miner, Singer and Baggett spent their interval away from formal Einstein Electric performances getting back to their roots in the fusion-minded Embius Trio. Now, with a renewed focus on experimental composition, the group is plugging back in, reintroducing rock to its jazz/Latin/blues/funk mix. Einstein Electric's absence might have been hard on its faithful following, but all will be forgiven once its patient fans rediscover the mystical allure of its seemingly eternal jams.