Jimi Hendrix made three historic studio albums in 1967 and '68. He spent the rest of his life laboring and failing to finish a fourth. But it was a rich if chaotic time, and we're not done with it. These studio jams and early stabs at evolving songs mostly come from 1969 as Hendrix worked with shifting lineups, indecisive about his post-Experience path. Three tracks date from a May session, his first with Billy Cox and Buddy Miles, the future Band of Gypsys, including a funky turn through the signature blues "Hear My Train A Comin'." A rough "Izabella" with his short-lived Woodstock band comes with a diving-jet solo. Of course, Hendrix plays at an elevated level in every setting: a workout with saxman Lonnie Youngblood; the overdubbed-guitar chorales in the '68 instrumental "Inside Out." Hendrix left us so much but in precious little time. Every shred counts.

“Help Me”

Joni Mitchell wrote and recorded this song for her album Court and Spark, but she had to switch from her regular band to make the song sound exactly the way she wanted. "I had attempted to play my music with rock & roll players," she told Rolling Stone. "They’d laugh, 'Awww, isn't that cute? She's trying to teach us how to play.'" Mitchell switched to a jazz band, Tom Scott’s L.A. Express, and scored the biggest hit of her career in the process.