When Jimi Hendrix walked out onto the stage of New York’s Fillmore East on Dec. 31, 1969, for the first of two shows that long night (with two more sets the following evening), he wasn’t only looking ahead to a new decade, but to a new Jimi Hendrix. He’d already put the Experience behind him and his new trio, Band of Gypsys, was intended as nothing less than a complete reboot. The songs they performed—all of the old ones were jettisoned—were funkier, deeper, darker. The new rhythm section, bassist Billy Cox (an old Army buddy) and drummer Buddy Miles (formerly of The Electric Flag), was less flamboyant than the Experience, coming from R&B rather than psychedelic rock. The original Band of Gypsys album, released in 1970, gave only a taste; it received mixed reviews at the time but, today, is considered a classic. This new set, the first of the four shows in its entirety, isn’t substantially different but it does contain moments that at least rival and occasionally surpass the original. The much-hyped title track is one of them: It spends its first few minutes as a slow boil, leading ultimately to a solo that embodies the full range and sheer audacity of Hendrix’s guitar playing. “Lover Man,” the show’s second number, and “Ezy Ryder” find the rhythm section uncaged and raring to bust loose—Hendrix is happy to oblige. Even a straight blues like “Bleeding Heart” transcends, opening Hendrix to new possibilities. Those possibilities were never to be realized: Band of Gypsys quickly imploded, Hendrix floundered throughout the year, and on Sept. 18, 1970, he was gone. Machine Gun, like the original Band of Gypsys LP, is more about promise than fulfillment.