Yes, it's Joni Mitchell, one of the most important singers and songwriters of the classic rock era. She's created far more than her fair share of unique, highly acclaimed albums -- including 1971's 'Blue' and 1974's 'Court and Spark' -- and her songs have been covered by some of the biggest names in music.
Don Felder was invited to join the Eagles while working with two-thirds of Crosby, Stills and Nash. Coincidentally he'd already worked with Stephen Stills by that time. Stills helped Felder form his first band in Gainesville while the future Eagle was still in high school. A few years ago Felder recalled how Eagles co-founder Bernie Leadon replaced Stills in his group. It's all connected.
Kevin Cronin of REO Speedwagon was in charge of the entertainment for his high-school prom, so he called up Jim Peterik of Ides of March, later of Survivor. The Chicago area was flush with rock talent in the late '60s and '70s, and apparently some were willing to play proms. REO Speedwagon was formed by University of Illinois students Neal Doughty and Alan Gratzer. Cronin would join five years later.
Forby Leonard Skinner is the man who inspired a southern-rock band to call itself Lynyrd Skynyrd. The gym teacher and high-school coach famously came down on Ronnie Van Zant and his friends for wearing their hair too long, although he later said that his alleged behavior was exaggerated. “They were good, talented, hard-working boys,” the late Skinner told the Florida Times Union. “They worked hard, lived hard and boozed hard.”