Music: "Both Sides of the Sky", Hendrix Estate Again Mines vault for "New" Music

Since the mid-Nineties, Kramer and Hendrix's estate have painstakingly Valleys of Neptune, in 2010 and followed it up with People, Hell and Angels three years later. Now they've slated a final volume, Both Sides of the Sky – which highlights the many changes in Hendrix's working life as he played with different configurations of musicians between 1968 and 1970 – for a March release.

Beginning with "Mannish Boy," a bluesy rocker that finds Hendrix singing along with his lead guitar lines, the record shows how much fun he was having at the time. In a rendition of "Lover Man," a speedy tune he was fooling around with since at least 1967's Are You Experienced, he interpolates the theme from TV's Batman. And on a country-inflected take on "Stepping Stone," the last single he released in his lifetime, he plays catcalls and schoolyard taunts on his guitar in between lyrics.

At the time of his death, most of the recordings on Both Sides of the Sky were unfinished by Hendrix's standards. "He probably would have revisited it and said, 'I can do that better,'" Kramer says. "He was never satisfied." But he says that doesn't undersell the brilliance of the music on Both Sides. Pointing to "Cherokee Mist" – a feedback-infused instrumental with an elastic melody that features Hendrix on sitar as well as guitar – he says, "At the very end, there's that incredible sound that he's getting out of his amplifier. It just sounds like a beast that got loose in the studio. It's primitive and wonderful."