Funny how the historic milestones can change over time. Consider Jimi Hendrix at Woodstock. Without even thinking, most would identify it as a pivotal moment, a culmination of the musical explosion that was the late Sixties.

The magnificently restored two-disc Live at Woodstock tells a slightly different story — of a ragged ensemble playing in a weird time slot (9 a.m. on Monday) and a musician in the middle of profound transition, grappling with big, still-coalescing ideas about fusing blues and rock and jazz improvisation. It becomes clear, after hearing this performance next to others in the "Experience Hendrix" series — notably Live at the Fillmore East — that while the restless Hendrix was determined to radically recast his material each time out, not every one of his sojourns ended up as a brilliant archive highlight.

Sure, there's that legendary version of "The Star-Spangled Banner," which Hendrix pitch-bent from patriotic warhorse into a defiant proclamation that sounded like it was written expressly for solo electric guitar. And there are several mood explorations that are breathtaking for their focus — notably the languid "Villanova Junction" and the savage fourteen-minute treatment of "Voodoo Child (Slight Return)." But his group was just beginning to understand the sweep of pieces like "Jam Back at the House" and didn't attain the ecstatic peaks Hendrix intended. That his vision isn't fully realized on Live at Woodstock somehow humanizes this deity. It's less a definitive portrait than a glimpse of an artist consumed by the pursuit, and its flaws underscore the supreme difficulty of his nightly quest.

“1999”

“I don’t consider myself a great poet,” Prince told Rolling Stone. “I just know I’m here to say what’s on my mind.” In the case of the apocalyptic party anthem “1999,” he was worried about then-president Ronald Reagan’s foreign policies. The song’s melody is based on a riff borrowed from the Mamas and Papas’ “Monday, Monday,” and Prince originally envisioned the first verse with three-part harmony but later split the vocals between himself and members of the Revolution. Because Warner Bros., with whom Prince was locked in a contractual battle, owned the original’s masters, Prince rerecorded the song and appropriately released that version in 1999.